05 Cobalt fuel problem

2005 Cobalt.No fuel. I have an 05 Cobalt.Wife drove home from work.I went out a few hours later to move it.It was a no start. Checked and it isn't getting fuel.Pulled the fuel pump and bought a used one with 13,00 miles (95,000 on ours ) .I also put in a new relay and checked the fuse & put in a new fuel filter.Still no fuel.Tested for current at connection where pump plugs in and there is current.Test light is not real bright.I don't have anything to do a voltage test with. When I turn the key to start,the fuel pump does not run.Getting Any suggestions? Thanks.

Tested for current at connection where pump plugs in and there is current.... When I turn the key to start,the fuel pump does not run.Getting Any suggestions? Thanks.

So there is NO power ever to the pump with the ignition set to run? Normally with the ignition cycled to run the FP will run, charge the line then cut off.

Joel

When I put the key in run position there is current. But when I put the plug for the fuel pump back in, the fuel pump is not running.I know it should charge the pump then shut down.But there is nothing from the FP.I pulled the plug on the pump at least a dozen times to check for current to the pump. Everytime it shows current at the plug terminal.I have a buddy turn the key off, then on.When the key is turned on, the test light lights up.When he turns it off, it goes out.But the light isn't bright when it is turned back on.So there is current to the plug located on the underbody pan behind the rear seat.But the fuel pump will not run. I don't know if it takes the full 12 V to run it. If the test light is right it shows a weak light. I would say the light is about half as bright as when running it right off the battery.I don't have a volt meter to check. Mine is broke. I learned not to slam the tool box lid down when your voltmeter is half in and half out. Thanks

Geez I wish I had some more ideas. Does your 2005 have a fuel pressure regulator on the fuel rail? I know most if not all the new GMs use pulse-width modulated control for the FPs now. Basically it's 'variable speed' control of the pump. It's all done thru the ECU and BCM. That might explain the dim test light you were seeing (lower voltage being sent to the pump). There's other 'permissives' that need to be met for the pump to run/continue running. I'm not knowledgeable there.

Joel

There is a valve (Similar to a tire valve) on the fuel rail. I'm at a loss on these new cars.I just know you need expensive equipment just to find a minor problem.I appreciate all the help and suggestions. Makes sense about the variable power to the fuel pump giving a dim light. Is there a way to test a fuel pump out of the vehicle ? Thanks.:runaround:

Yep, the book name for them is Shrader valve. It's basically a test and purge point on the fuel rail. You should get a serious spray of fuel out of there with the key to run or engine on. I dunno the specs of what the PSIG should be.

Joel

the Schrader valve is for a fuel pressure gauge to be attached to, not to stick things in and see if you get "a serious spray of fuel" :rofl: While I don't know the spec offhand (I think it's at least high 40s), I know the ecotecs will run, although not well, on as little as 15 PSI.

My buddy talked to a retired GM mechanic. He seems to think the fuel pump that came with the car, and the used one I bought are both junk. I have a 30 day warranty on the used one. I just don't know how to test it. The guy at the yard said to hook up a 12V wire to the hot and the ground to a ground. I'm going to take the pump I took out of the car to the junkyard tomorrow and see if they want to test it.If it doesn't work, then I take the other pump out and try it. The car is at a friends house and it's 20 miles each way.So don't want to make a trip if I don't have to.My vehicle I use now is a 1977 Dodge M880 3/4 ton pickup 4 wheel drive with 4:10's. I get 8 MPG with the wind at my back going downhill. That's why it only has 66,000 miles on it. Again,thanks to all who help.It is VERY much appreciated.

the Schrader valve is for a fuel pressure gauge to be attached to, not to stick things in and see if you get "a serious spray of fuel" :rofl:.

Sure, but it is a quick redneck 'troubleshoot' point!:icon16:

UPDATE - I took the fuel pump that was on the car to the yard where I bought the used one. They bench tested it and it is good. So that would mean the problem is elsewhere in the electrical / computer system. :confused:

Sure, but it is a quick redneck 'troubleshoot' point!:icon16: You don't need to tell me about redneck testing... I've done 'em all, check out the truck in my sig and avatar (before lift and wheelbase mod), tell me that don't say redneck all over it :) I'd be lying if I said I'd never done the spray test, but I'm always worried about potential liability (as screwed up as the "justice" system is) from telling someone that and have them do it 3 ft. from a space heater while his buddy lights a cigarette and throws the match under the car... and have them end up owning my house and cars.

UPDATE - I took the fuel pump that was on the car to the yard where I bought the used one. They bench tested it and it is good. So that would mean the problem is elsewhere in the electrical / computer system. :confused:

Just to clarify the electrical measurements, current is amps and is measured with a meter either a clamp-on inductive meter or an inline meter. This must be done with the circuit intact because you are measuring the amperage that the pump is using. Voltage is electrical "pressure" and can be checked with the pump unplugged, it sounds like that's probably what you were checking when you said you had current to the pump?

Check and see if the fuel system has a regulator on the fuel rail or not. I have an '04 Cavalier which does have a regulator and return line, but I think all Cobalts regardless of year have a returnless system that uses the pulse-width modulation that Rodeo02 mentioned. These must be pretty good cars, I havn't seen one except for a battery problem, so I'm not familiar at all with them. If it is returnless, try unplugging the fuel pressure sensor (what tells the PCM what duty cycle to command). I would assume that would make the pump run at some "should work most of the time" duty cycle. If that makes the pump run, chances are the sensor is reading a pressure over what should be there, so the PCM is not commanding the pump on. Not all returnless systems are pulse-width modulated, some have the regulator in the fuel pump module.

You'll be miles ahead if you buy a new DVOM, especially one that has a frequency/duty cycle measurement on it. Also, if you didn't check for a good ground to the pump, do that before you do anything else.

EDIT: I got to thinking about it, and if you replaced the fuel pump relay, then most likely it is not pulse-width modulated. A relay is just a magnetically operated switch, which is incapable of switching as fast as necessary to control a motor's speed (and would weld the contacts together in no time). It's not impossible that the relay is just a safety measure to be sure that power can be cut when needed, but the output to the pump would have to come from a transistor inside the PCM.

You don't need to tell me about redneck testing... I've done 'em all, check out the truck in my sig and avatar (before lift and wheelbase mod), tell me that don't say redneck all over it :) I'd be lying if I said I'd never done the spray test, but I'm always worried about potential liability (as screwed up as the "justice" system is) from telling someone that and have them do it 3 ft. from a space heater while his buddy lights a cigarette and throws the match under the car... and have them end up owning my house and cars.



Just to clarify the electrical measurements, current is amps and is measured with a meter either a clamp-on inductive meter or an inline meter. This must be done with the circuit intact because you are measuring the amperage that the pump is using. Voltage is electrical "pressure" and can be checked with the pump unplugged, it sounds like that's probably what you were checking when you said you had current to the pump?

Check and see if the fuel system has a regulator on the fuel rail or not. I have an '04 Cavalier which does have a regulator and return line, but I think all Cobalts regardless of year have a returnless system that uses the pulse-width modulation that Rodeo02 mentioned. These must be pretty good cars, I havn't seen one except for a battery problem, so I'm not familiar at all with them. If it is returnless, try unplugging the fuel pressure sensor (what tells the PCM what duty cycle to command). I would assume that would make the pump run at some "should work most of the time" duty cycle. If that makes the pump run, chances are the sensor is reading a pressure over what should be there, so the PCM is not commanding the pump on. Not all returnless systems are pulse-width modulated, some have the regulator in the fuel pump module.

You'll be miles ahead if you buy a new DVOM, especially one that has a frequency/duty cycle measurement on it. Also, if you didn't check for a good ground to the pump, do that before you do anything else.

EDIT: I got to thinking about it, and if you replaced the fuel pump relay, then most likely it is not pulse-width modulated. A relay is just a magnetically operated switch, which is incapable of switching as fast as necessary to control a motor's speed (and would weld the contacts together in no time). It's not impossible that the relay is just a safety measure to be sure that power can be cut when needed, but the output to the pump would have to come from a transistor inside the PCM.


The only thing on the fuel rail is the Schrader valve. Near the fuel tank is a small tank that is a fuel tank pressure sensor. I've done the push the valve test also. On this car all I got was a very small psssh and literally a drop of gas.When the car first wouldn't start the first thing that crossed my mind was fuel pump. Had the wife turn the key while I stood beside the car and listened. We both heard the fuel pump cycle. So I had her do it again. This time nothing. We tried it at least a dozen more times, and still nothing. I have a wiring diagram and see there is a FUEL PUMP RELAY CONTROL. It shows this in the rear of the car.This is located in the PCM Along with the generator terminal output. I bet that item won't cost more than 4 or 5 grand !! I am going either Saturday afternoon,or Monday afternoon to see what I can do on the car. Thanks again for the help, always aprreciated. :banghead: - Me :shakehead -My wife

Great info J-Ri. To the OP; Are you getting any codes at all? Do you have a CAN compliant code reader to check? Is it possible the fuel pump won't fire due to not seeing a signal from the crankshaft position sensor or the likes? Could you have a chewed wire somewhere?

Joel

Great info J-Ri. To the OP; Are you getting any codes at all? Do you have a CAN compliant code reader to check? Is it possible the fuel pump won't fire due to not seeing a signal from the crankshaft position sensor or the likes? Could you have a chewed wire somewhere?

Joel

I don't have a code reader. Can't ruleout a chewed wire some place. I checked the wires that are visible. Because of the poor design of a lot of items on this car I can't rule out anything. I hit a racoon 3 years ago.Over $800.00 in damages. Because there is no support, or protection, under the radiator it took it and the a/c condensor out. Not realizing a racoon would do that damage, by time I got home the car overheated. That cost me the head gasket.I haven't fixed it yet. Used a sealer that has held up good so far.But the check engine light came on a few times due to bad gas. If anyone around the PA,Ohio, W VA area uses the same gas, they will have problems. I won't mention the Gaz Stazions name though. I eat there, but never ever will buy the gaz again. I got gas at another station and the light went out and the rough running cleared up.But anyhow the check engine/ service engine light came on around 75,000 miles and has stayed on. I figured with the head gasket problem it might have been the O2 sensor. I get in the catch 22, if I buy a code reader, no money for parts. But I have never been called smart.Probably, no - should have, bought the reader and went from there. Problem is we moved my Mom in with us because she has Alzheimers. So I had to quit work to care for her.My wife works and that barely pays the bills.Other than the normal change oil and filters (air, oil) the only other thing I did was change the spark plugs.

Whoa dude you've got ALL kinds of stuff going on. So the 'coon thing happened when the car was basically new? That sucks. FWIW, none of them have any protection up/around the radiator anymore. Overheating in an all aluminum engine is major bad news, but if it happened 3yrs ago and a dab-o-goo has held you off since then, I'd think you're good to go. The only odd-ball 'chewed wire' concern I'd heard of in regards to a delta chassis was with the vehicle speed sensor. It got munched, basically the car wont shift, dash no workie, a mess. If you've pulled the battery a bunch of times and the car hasn't run since, I'm not sure if you'd get a good code read now anyway. I'd still try anyway. I know the ~$40 OBDII with CAN from ChinaFreightTools works like a champ (Harbor Freight Tools).

Joel

Whoa dude you've got ALL kinds of stuff going on. So the 'coon thing happened when the car was basically new? That sucks. FWIW, none of them have any protection up/around the radiator anymore. Overheating in an all aluminum engine is major bad news, but if it happened 3yrs ago and a dab-o-goo has held you off since then, I'd think you're good to go. The only odd-ball 'chewed wire' concern I'd heard of in regards to a delta chassis was with the vehicle speed sensor. It got munched, basically the car wont shift, dash no workie, a mess. If you've pulled the battery a bunch of times and the car hasn't run since, I'm not sure if you'd get a good code read now anyway. I'd still try anyway. I know the ~$40 OBDII with CAN from ChinaFreightTools works like a champ (Harbor Freight Tools).

Joel


When I saw all the damage the coon did that really made me mad. I know a lot of others don't have any protection there either. I should have known when I first got it, to get rid of i. I had assumed it was a rehased Cavalier. Then find out it was actually a new car. Opel Chevy mix.But yet a new car. I had the luck of getting the one that had the radio that kept going into lock, brake light would come on going around a bend and a lot of trim issues. Took it back for warranty work.Said they couldn't duplicate the brake light and fixed the radio.Get it home and the same day the radio goes into lock. Make the turn to come home and the brake light comes on.So I do some research. Find out that they had a bad brake sensor and faulty radios. So I take it back to the dealer.I tell them that the Cobalts have a brake sensor issue and the radio problem is also a common problem. I get the deer with the headlights in its eyes look. I tell them heres the deal, the car stays here till it is fixed right. While I'm telling them this a service tech walks in. He asks what the problem is. I tell him. the guys at the desk say there aren't any bulletins on the problems. He said Oh yes there is. Went on the computer and pulled them up. He told them if it isn't on paper - Look it up on the computer. So they put in an upgrade radio and a new sensor for the brakes. Haven't had a problem on either since.I realize it's a cheap car.But the cheap interior, got to go.It is below sub standard.I like the way it rides, looks and handles. We took 2 trips to Florida from PA. to visit my wifes family. We got a low of 38 miles to the gallon . We got as high as 48 MPG.That was doing it the old fashioned way.Check the miles vs the gallons used. Not the onboard computer.
OK, Now here is what I did today on it. I checked the ground. It is good. I checked to see if it is getting power to the fuel pump pressure tank. It is. So if it is getting power to both, what am I missing ? I noticed on the tank where the wires go into the plug that the unit looks like it should come out of the tank.It has what resembles a bayonet type mount.I also pushed in the Schrader valve. The first time I got a good air blast with more fuel that ever (but still not much ). I went back under and wired the fuel pump direct I let it run for maybe 3 seconds. Went abck and pressed the valve, no air, no gas.Back under to jump pump.Let it run about 5 seconds.Back out and push Schrader, nothing. Did that about 3 more times. Nothing.Gave up considered pouring gas over whole car and lighting it :evillol:.But then thought my buddy would not appreciate it because it is in the bottom of his barn :grinno:!!! :banghead: :banghead: :banghead: :crying:

Everything is so computer/software driven today, that I'm thinking you've done all you can and need a scan with a Tech-II or what ever the Good Wrench dudes use to 'see' everything that's going on.

56Pontiac, I'm wondering if maybe the replacement pump was bad... even if the motor ran it doesn't necessarily mean the pump was pushing anything. If you're jumping power to the pump, it should have pressure at the schrader valve. Are you sure you have the polarity right? Reverse polarity will give no pressure but will make the pump run. Pull the pressure line off of the pump and clamp a hose over it going into a container suitable for fuel and run the pump. Just be very careful of sparks, I'd use long wires attached to the pump and then make the final connection away from the pump, I'd stay at least 10' away and make the connection a foot or two above the ground. If you've got fuel coming out there, you have a restriction in the line somewhere, maybe try blowing compressed air backwards through the line? There is also sometimes a small screen where the fuel line connects to the fuel rail, see if that is plugged. If there is no fuel there and you have the polarity correct, you have a bad pump.

Rodeo02, I work at an independent shop but we have a Tech-II, and really all you can do on it for this problem is command the fuel pump on, which can be done with jumper wires. Granted, it's much easier and faster than dropping the tank, but it's not as capable as everyone thinks. The only thing you need it for is SPS updates and a few body computers (radio, on-star, etc.). For the money, the Snap-on MODIS is much better (ignoring the proprietary GM software). The Tech-II is grayscale and has constant "scan lines" (or what were scan lines with a CRT, dunno for sure what LCD woud be called) if the car is running or has a battery charger on it. It also has no internal battery, which is at the very least irritating. It can also only graph 3 lines at once, and they have to be on the same graph.

56Pontiac, I'm wondering if maybe the replacement pump was bad... even if the motor ran it doesn't necessarily mean the pump was pushing anything. If you're jumping power to the pump, it should have pressure at the schrader valve. Are you sure you have the polarity right? Reverse polarity will give no pressure but will make the pump run. Pull the pressure line off of the pump and clamp a hose over it going into a container suitable for fuel and run the pump. Just be very careful of sparks, I'd use long wires attached to the pump and then make the final connection away from the pump, I'd stay at least 10' away and make the connection a foot or two above the ground. If you've got fuel coming out there, you have a restriction in the line somewhere, maybe try blowing compressed air backwards through the line? There is also sometimes a small screen where the fuel line connects to the fuel rail, see if that is plugged. If there is no fuel there and you have the polarity correct, you have a bad pump.




Rodeo02, I work at an independent shop but we have a Tech-II, and really all you can do on it for this problem is command the fuel pump on, which can be done with jumper wires. Granted, it's much easier and faster than dropping the tank, but it's not as capable as everyone thinks. The only thing you need it for is SPS updates and a few body computers (radio, on-star, etc.). For the money, the Snap-on MODIS is much better (ignoring the proprietary GM software). The Tech-II is grayscale and has constant "scan lines" (or what were scan lines with a CRT, dunno for sure what LCD woud be called) if the car is running or has a battery charger on it. It also has no internal battery, which is at the very least irritating. It can also only graph 3 lines at once, and they have to be on the same graph.


The pump wont run at all from a command from the vehicle.I had to jump it from a hot wire I made that went from the battery in the trunk to the fuel pump.The old pump run when running a hot/ground wire. I'll try to see if it pumps actual gas like you say. I ordered a CEN TECH Code Reader CAN OBDll from Harbor Freight. Couldn't afford anything better. I know that when I test the contact coming out of the plug on the back of the pan behind the seat (Where the fuel pump plug is located ) that it does show power to it.But when I turn the key to start, the fuel pump won't run. If I jump wire it you can hear it. I will check to make sure the pump(s) actually pump and do not just run.Thanks,appreciate the help.

The pump wont run at all from a command from the vehicle.I had to jump it from a hot wire I made that went from the battery in the trunk to the fuel pump.The old pump run when running a hot/ground wire. I'll try to see if it pumps actual gas like you say. I ordered a CEN TECH Code Reader CAN OBDll from Harbor Freight. Couldn't afford anything better. I know that when I test the contact coming out of the plug on the back of the pan behind the seat (Where the fuel pump plug is located ) that it does show power to it.But when I turn the key to start, the fuel pump won't run. If I jump wire it you can hear it. I will check to make sure the pump(s) actually pump and do not just run.Thanks,appreciate the help.


UPDATE; Ok, I found out that there are 3 red hot wires to the plug for the fuel pump.They were covered with tar and only saw 2. The one that is getting power is the fuel gauge. Neither of the other 2 have power when the key is turned on.Had my buddy turn the key on while I had the test light on the terminals.Nothing.So we tested the fuse. There is no power to the fuse block for the fuel pump.All other fuses that should have power to them do. But the one for the pump is totally dead.I had checked earlier for blown fuse and changed the relay.The fuse was good, but changed it anyhow. Still waiting for the Code reader I ordered. FedEx is slower than Molasses in January. According to the tracking it won't be here for a week yet.Thanks again for the help. :banghead:

A tip for the future, don't check to see if a fuse is blown, check for power to both sides of the fuses. It's quicker than removing the fuses to check them, and it shows if they have power to them as well. There are dual LED test lights that have a clamp for power an ground, then one color lights for hot and the other lights for ground. You can check every fuse and both sides of the circuit in about a minute. Hot both sides, fuse is good and has power; hot one side ground on the other, fuse is blown but the rest of the circuit is good; ground to both sides, fuse is good but doesn't have power. This is how I do it, so when you said the fuse was good, I assumed the wiring was good as well.

To test it further, run a fused jumper wire of the appropriate amperage to the "after" side of the fuse. All the fuses in that row of the box will get their power from the same side, so put it to the other side and see if it starts/runs. If it does, you can put the tank back up. You'll need a wiring diagram to see where the power for the fuel pump fuse comes from. Sometimes they go straight to B+ through a splice in the fuse box, other times they are one of several fuses that go through a larger fuse. That means that if you have checked every single fuse everywhere else on the car and the only fuse with no power to it is the fuel pump fuse, there is a problem in the wiring. Common places GM hides fuses from you include: Under the hood (can have multiple), both sides of the dash where the door closes against, under the dash, in the center console, under the rear seat, in the trunk. I havn't had to find them on a Cobalt yet, so check all those places for extra fuses, and don't look at it logically either (you need to think like an engineer). A wire can go from the battery and then through 3 fuse panels in different parts of the car before it goes to the device. You're getting very close to finding the problem, and it will probably be a cheap repair too.

To test it further, run a fused jumper wire of the appropriate amperage to the "after" side of the fuse. All the fuses in that row of the box will get their power from the same side, so put it to the other side and see if it starts/runs. If it does, you can put the tank back up. You'll need a wiring diagram to see where the power for the fuel pump fuse comes from. Sometimes they go straight to B+ through a splice in the fuse box, other times they are one of several fuses that go through a larger fuse. That means that if you have checked every single fuse everywhere else on the car and the only fuse with no power to it is the fuel pump fuse, there is a problem in the wiring. Common places GM hides fuses from you include: Under the hood (can have multiple), both sides of the dash where the door closes against, under the dash, in the center console, under the rear seat, in the trunk. I havn't had to find them on a Cobalt yet, so check all those places for extra fuses, and don't look at it logically either (you need to think like an engineer). A wire can go from the battery and then through 3 fuse panels in different parts of the car before it goes to the device. You're getting very close to finding the problem, and it will probably be a cheap repair too.


The only other fuses that didn't power were the lights.They work, so they wouldn't power I guess till they are turned on.But every other fuse had power.The fuel pump relay ( In the fuse block ) can be heard clicking when the key was turned on.I did put a total of 3 different relays in and also changed the fuse.I've had fuses that looked good before and weren't.Didn't want to make that mistake again. But no power to either fuse. Next time I can get at the car will probably be Monday.So I'll do all that you suggested. My buddy had a Cavalier that had the same problem.He couldn't find why there was no power to the fuel pump. he decided to junk it.Him and another buddy started to tear it apart. When they took the dash out, a wire from the ignition was off.It was too late for that car !!Thanks,appreciate the info.

The relay clicks because the control side which activates the magnetic coil which pulls on the "switch" part of the relay and closes the circuit is good. From there, power flows through the "switch", but you have no power there which is why I suggested running a fused jumper wire to the after side of the fuse. Assuming the circuit between the fuse and the relay is good, the car should start as soon as all the air clears out of the fuel lines and rail.

The relay clicks because the control side which activates the magnetic coil which pulls on the "switch" part of the relay and closes the circuit is good. From there, power flows through the "switch", but you have no power there which is why I suggested running a fused jumper wire to the after side of the fuse. Assuming the circuit between the fuse and the relay is good, the car should start as soon as all the air clears out of the fuel lines and rail.


First chance I get to go work on it I will try the jumper wire.Monday might be the soonest I can get at it. It's about a 25 minute to 1/2 hour drive each way. Thanks again.

Jump wired the fuel pump from another fuse. The pump runs. I put the tank back up in and it took a while to get the car started.Took the plugs out ( Can ony get 3 out.One is in so tight I'm afraid of stripping the threads. Using a 3/8 ratchet with a 12" extension the extension is bowig under the pressure ) and bead blasted them.It finally started. But it runs for maybe a minute at the longest and shuts down.It starts right back up again.I had noticed a kink in the hard plastic line going to the pressure tank (happened from having the tank suspended for so long I guess ) .I had squeezed it,but still has a narrow area where it was slightly bent.It seems like the problem with it not staying running is fuel related.It will kind of sputter and pop a little. Not an outright backfire.Next time I have a chance to work on it I think I'll drop the tank again and check to make sure that line isn't closed more than I think it is.I wouldn't think that the pump running all of the time should cause a fuel problem because I assume the excess fuel just goes back through the return line to the tank. At least it was great to hear it run for the first time in about 7 months. Thanks :grinyes:

Good to hear that it runs!

Find and fix the open in the wire between the fuse and battery, there's a chance that interfering with the circuit you jumped power from could be causing voltage problems for both circuits and making the engine die. After you do that (and if it still dies), I'd check the fuel pressure before dropping the tank again, these engines don't need even close to the 3/8" line that they have, mine will idle for 20 minutes on 12 oz of fuel injector cleaner which flows in through a 1/16" line. They use the same size line on almost all GM vehicles, the 454 V8s have the 3/8" just like our cars do. If that line was kinked to the point that it turned white on the sides where it was flat, I'd fix it, otherwise it's probably fine. They say "non-repairable" on them, but that just means with rubber hose. Carquest (and probably others) have repair kits for the hard nylon lines, you just have to use the parts in the kit, no using rubber hose or screw-clamps.

For that stuck plug, spray a little bit of penetrating oil down the hole and let it sit overnight or between working on it. That should make it much easier to get out. I've had some that were stuck pretty good, and I think I twisted my 12" extension about 1/8 of a turn before the plug came out with no problems. When you reinstall them, apply a light coating of nickel or copper (NOT the glass bead stuff) based anti-seize to the threads and the plug seat. Just don't get any on the electrode or you'll get a misfire if it bridges the gap. They'll turn out with no problem next time if you do that.

Good to hear that it runs!

Find and fix the open in the wire between the fuse and battery, there's a chance that interfering with the circuit you jumped power from could be causing voltage problems for both circuits and making the engine die. After you do that (and if it still dies), I'd check the fuel pressure before dropping the tank again, these engines don't need even close to the 3/8" line that they have, mine will idle for 20 minutes on 12 oz of fuel injector cleaner which flows in through a 1/16" line. They use the same size line on almost all GM vehicles, the 454 V8s have the 3/8" just like our cars do. If that line was kinked to the point that it turned white on the sides where it was flat, I'd fix it, otherwise it's probably fine. They say "non-repairable" on them, but that just means with rubber hose. Carquest (and probably others) have repair kits for the hard nylon lines, you just have to use the parts in the kit, no using rubber hose or screw-clamps.

For that stuck plug, spray a little bit of penetrating oil down the hole and let it sit overnight or between working on it. That should make it much easier to get out. I've had some that were stuck pretty good, and I think I twisted my 12" extension about 1/8 of a turn before the plug came out with no problems. When you reinstall them, apply a light coating of nickel or copper (NOT the glass bead stuff) based anti-seize to the threads and the plug seat. Just don't get any on the electrode or you'll get a misfire if it bridges the gap. They'll turn out with no problem next time if you do that.

Thanks again. I'll check the wire next time I get out to the car. My problem is that I have to stay home and keep an eye on my Mom who has late stage Alzheimers.My wife works and I can't leave my Mom alone.Area Agecy On Aging comes out this week to see her.Then we have to start the hated process of putting her in a home. I don't have a garage and have the car at a friends place in the bottom of his barn.If the car were here I'd be able to spend more time on it.Thanks.

All else fails with that stuck spark plug; Did you try to snug it slightly first? I've had luck getting them out of aluminum that way. Definitely try PBblaster or the likes first.

Joel

All else fails with that stuck spark plug; Did you try to snug it slightly first? I've had luck getting them out of aluminum that way. Definitely try PBblaster or the likes first.

Joel


We did try to snug it after we tried to loosen it.Seemed like it did just that ....made it tighter.I was going to put PB Blaster on it and forgot. If I don't get it out now it will get done when I change the head gasket. Hate the aluminum junk.Never liked it, never will. Aluminum to lighten the load to up the MPG as per what the Govt wants. Wish they would get rid of the cat, put on a less restrictive exhaust and eliminate all the pollution garbage and pick up more MPG's that way. Then go back to cast iron. Then get on China's case who pollutes more than every other country combined.Thanks and I will post what happens next time I work on it.

If the plug did tighten, then the threads can either move freely or are already stripped, I'd just back it out and cross your fingers. I've done more spark plugs than I can count in aluminum heads, at first I thought the threads would pull out on half of them, but I havn't had a single one pull any out. The funny thing is, the only time I did have the threads pull out was on a cast iron head :)

I know what you're saying about aluminum, but it definitely has it's upsides too. A Cavalier with the cast iron 2.4l handles and rides worse than the same car with the 2.2 Ecotec. Not much, but it is noticeable if you really get going :). You also have more HP to accelerate because you're not moving all that weight with you. The latest version of the 2.4 Quad4 makes 5 HP more than the 2.2 Ecotec, yet is slower.

Use anti-seize, change fluids on time, and use a torque wrench... pretty much all you need to do with aluminum.

If the plug did tighten, then the threads can either move freely or are already stripped, I'd just back it out and cross your fingers. I've done more spark plugs than I can count in aluminum heads, at first I thought the threads would pull out on half of them, but I havn't had a single one pull any out. The funny thing is, the only time I did have the threads pull out was on a cast iron head :)

I know what you're saying about aluminum, but it definitely has it's upsides too. A Cavalier with the cast iron 2.4l handles and rides worse than the same car with the 2.2 Ecotec. Not much, but it is noticeable if you really get going :). You also have more HP to accelerate because you're not moving all that weight with you. The latest version of the 2.4 Quad4 makes 5 HP more than the 2.2 Ecotec, yet is slower.

Use anti-seize, change fluids on time, and use a torque wrench... pretty much all you need to do with aluminum.


What I don't like about aluminum is the heat factor. When I hit the racoon I never expected it to take out the cooling system. Something that you don't think of. It was about a mile from home.The wife take the car to work the next day ( 20 miles one way ) and calls me that the CHECK ENGINE light came on.She said she checked it and saw there was no water in it. I drove down and said let it set, the rad and a/c are gone.So called the Insurance company. They send a guy down the next day with a flat bed. I told him Don't start the car. Oh, he said, it won't take long. So he starts it up, doesn't like where it was and backs it off. Does this twice. the gets out (car still running ) and walks around to make sure he likes where it is on the flatbed.Finally after about 10 minutes it gets shut off. The next afternoon I get a call - Hey this is Steve down at the body shop. I'm driving this Cobalt around and am I missing something I don't see anything wrong with it ? My exact words - You idiot there isn't any coolant in it. Oh !! That was his reply. I told the wife well with all that cars been thorugh, there is no doubt the head gasket isn't long for this world. Didn't last a month. All I can hope is the head is OK. But knock on wood, I've never stripped a plug yet.I come from the days of the 265's, 283's, 327's and the Fords I've had were the 390's and 429's. I have a 28 Ford Tudor Sedan, 56 Pontiac 2 door wagon and a 79 Firebird. My everyday truck is a 77 Dodge M880. I'll still take the older ones over the new ones. Thanks

Sounds like that car's had some bad luck and a couple incompetent service guys in it's few years. The head gaskets don't last long if they overheat very much.

I love the older ones too, if I could afford the gas I'd drive my old '86 truck every day. I just drive too far to get single-digit MPGs. It's had some very hard use over the years, but still runs perfect... starts every time, I don't think I've done anything but oil changes in 10k miles. In the near future I'll be looking for an older Caprice and fixing that up, adding tons of HP, maybe even restore it if I start feeling ambitious. Nobody today makes a car that I really want to buy... except a new Camaro, but for the money I'd spend on the SS trim on that I could have a better, mostly custom, classic car. It's a hard decision.

What I don't like about aluminum is the heat factor. When I hit the racoon I never expected it to take out the cooling system. Something that you don't think of. It was about a mile from home.The wife take the car to work the next day ( 20 miles one way ) and calls me that the CHECK ENGINE light came on.She said she checked it and saw there was no water in it. I drove down and said let it set, the rad and a/c are gone.So called the Insurance company. They send a guy down the next day with a flat bed. I told him Don't start the car. Oh, he said, it won't take long. So he starts it up, doesn't like where it was and backs it off. Does this twice. the gets out (car still running ) and walks around to make sure he likes where it is on the flatbed.Finally after about 10 minutes it gets shut off. The next afternoon I get a call - Hey this is Steve down at the body shop. I'm driving this Cobalt around and am I missing something I don't see anything wrong with it ? My exact words - You idiot there isn't any coolant in it. Oh !! That was his reply. I told the wife well with all that cars been thorugh, there is no doubt the head gasket isn't long for this world. Didn't last a month. All I can hope is the head is OK. But knock on wood, I've never stripped a plug yet.I come from the days of the 265's, 283's, 327's and the Fords I've had were the 390's and 429's. I have a 28 Ford Tudor Sedan, 56 Pontiac 2 door wagon and a 79 Firebird. My everyday truck is a 77 Dodge M880. I'll still take the older ones over the new ones. Thanks

Latest in the COBALT SAGA. Went to my buddies last night. Fired the Coablt up, and as usual it stalled afetr about 10 seconds.Checked the fuse to make sure it wasnt a timed fuse.It wasn't.So I sat in the car and kept pumping the gas to keep it going.After minute or so of that I let off.The car ran maybe 30 seconds on it's pwn.So back to pumping the gas.After the water temp go up to about 140 I let off the gas.It ran for about 90 seconds. So back to pumping.After the temp got to 160 I got off the gas.It stayed idleing.So I let it warm up for 10 minutes.Shut it down and fired it up a few times.Ran good.So I drove it home (about 25 minutes ) and got on it going up some steep hills (PA mountains !! ) It ran flawless all the way home. Of course the fuel pump is running all the time. Went out this morning and again to get it to run I had to keep pumping the gas. Once it warms up, it's great.Bought some LUCAS injector cleaner and put that in the tank. Will put some fresh gas in it today and see if that helps.I'm also goingto replace the plugs. They only have about 4,000 miles on them, but have been through a lot and have been bead blasted.The Harbor Freight code reader - waste of 40 bucks.Hooked it up and got the N/A .So that means it won't work on the Cobalt.It is CAN updated. So far that's where the Cobalt is at.

...The Harbor Freight code reader - waste of 40 bucks.Hooked it up and got the N/A .So that means it won't work on the Cobalt.It is CAN updated. So far that's where the Cobalt is at.

Good to see you're making headway on this! Weird about the ~$40 China Freight reader though :confused:. A co-worker of mine bought one for his truck. I tried it on my 2007 Cobalt and it works like a champ. I had no codes to scan, but it goes through it's routine and comes up clear. No error messages or N/As.

Joel

Latest in the COBALT SAGA. Went to my buddies last night. Fired the Coablt up, and as usual it stalled afetr about 10 seconds.Checked the fuse to make sure it wasnt a timed fuse.It wasn't.So I sat in the car and kept pumping the gas to keep it going.After minute or so of that I let off.The car ran maybe 30 seconds on it's pwn.So back to pumping the gas.After the water temp go up to about 140 I let off the gas.It ran for about 90 seconds. So back to pumping.After the temp got to 160 I got off the gas.It stayed idleing.So I let it warm up for 10 minutes.Shut it down and fired it up a few times.Ran good.So I drove it home (about 25 minutes ) and got on it going up some steep hills (PA mountains !! ) It ran flawless all the way home. Of course the fuel pump is running all the time. Went out this morning and again to get it to run I had to keep pumping the gas. Once it warms up, it's great.Bought some LUCAS injector cleaner and put that in the tank. Will put some fresh gas in it today and see if that helps.I'm also goingto replace the plugs. They only have about 4,000 miles on them, but have been through a lot and have been bead blasted.The Harbor Freight code reader - waste of 40 bucks.Hooked it up and got the N/A .So that means it won't work on the Cobalt.It is CAN updated. So far that's where the Cobalt is at.

Check that the ECT sensor is reading right, an incorrect reading does more harm before the engine is up to temp

Good to see you're making headway on this! Weird about the ~$40 China Freight reader though :confused:. A co-worker of mine bought one for his truck. I tried it on my 2007 Cobalt and it works like a champ. I had no codes to scan, but it goes through it's routine and comes up clear. No error messages or N/As.

Joel
From the few products I actually bought from them, I think everything they sell is junk. I've got a dead-blow hammer that's ok. I bought a balljoint separator that snapped the first time I used it to separate the tie rod ends on my truck. I have a set of prybars that are so weak all they're good for is pushing a belt on a pulley I can't reach by hand. I had a ratchet that broke just pulling on it by hand, my Matco ratchet at work has had a 3' cheater bar on it! One of my friends bought a set of jack stands, the release lever broke off the ratchet/lock part. While I was looking at it, I noticed the weld penetration was horrible on the frame, and that it wasn't even welded all the way along the seam! I try to buy American anyway, unless there is no way around it. Have you ever looked for a made in USA hand operated can opener or toenail clippers? :shakehead We used to make good products, and if not challenged by "disposable" products from China, I think we still would.

Here is the latest.I put the Code Scanner on again. Three times it read N/A.On the fourth try it said there were 3 codes. It gave me the faults for 2 of the 3.One was for an intermittent miss. Don't remember the other off hand.So even though the plugs were new before the problem, I changed the 3 that I could get out.I also filled the tank with fresh gas (There is a place in PA that has gas that I will never buy again. (I won't mention the namez of the place.More into this later ) and put more Lucas cleaner in it. After changing the plugs I fired it up.It ran smooth and the miss was gone. The engine light has been on for the past 40,000 miles.Now last night,the light went out and has stayed out.No,it didn't burn out.Checked that. There are no codes on the car now.I still have to trace the fuel pump wire to get it on the right one. It is still hooked to another fuse.So the pump runs all the time.As it stands the car is running like new.Back to the gas problem. When the engine light first came on I knew it was bad gas.So after I ran it down to a 1/2 tank I filled it up at another place.After a few miles the light went out.Didn't learn my lesson and got it there again. Same thing, same remedy.So I emailed them and asked what they added to their gas.They would NOT give me a straight answer.Gave me crap about they had filters that go down to millions of microns etc. I emailed them back.Told em I didn't say DIRT, I said additives.Still would not give a straight answer. I do know that methanol is bad for vehicles.Having worked for a time at AMOCO we had to learn about additives.Methanol has an adverse reaction with zinc in the gas tanks (No problem with plastic tanks now ) and with the plastic,rubber etc. in the fuel system. Plus it just doesn't do a car good.Dry gas is Methanol.So Isopropyl dry gas is the best. Anyhow, some places cut the gas with Methanol. That's why I wanted to know what additives they used. Upon talking to others I go to find out they had the same problm.Others don't realize the problems with their vehicles are from the gas.But my wife forgot once and got gas there.As I was driving the car started to miss and the light came on.I said I didn't use the S***Z brand gas and it did it again.She said - Oh I forgot and put it in last night.She won't make that mistake again I hope. So my feelingz are thiz place should stick to making food productz and selling cigarettez and quit selling gaz.I did try to get the spark plus out again that won't come out. I soaked it with PB Blaster over night.Treid to turn it.Nothing.So I treid to tighten it a little.It did go a little.So then tried to loosen it again.Went maybe a 1/16 of a turn.So tighten and spray again.Turned out about the 1/16 only again.Fired it up and let it warm. treid again. Goit maybe an 1/8 this time.Then tighten and loosen.Won't go beyond that 1/8 pr sp turn.But does make this God awful screeching sound of - I am tight and staying right here. treid it again the next day again after spraying it with PB. Same result.So I have 3 new plugs and one old one. I appreciate all hte help from everyone. I hate the Chinese junk.I worked on the Steel Mills near Pittsburgh for 12 years till the shutdown. The way I look at it in this economy if your out of work and driving a Japanese car and shop at the nations biggest retailer and buy the Chinese junk - then eat the Japanese car and Chinese junk.I shop at the small town stores. Might pay more sometimes, but it's worth it. I bougth filters for the Coablt at a major discount auto parts store. They were $2.00 on average cheaper than the BIG Discount store.Oil was .75 cents a quart cheaper. If you think the stuff sold in the Big store is the quality, guess again. Aagin - appreciate all the help from everyone.Can't say it enough and couldn't have done it without you.:rofl::iceslolan:naughty::loser:

The Cobalt ran good for about a day. Then it started running rough. It seemed like bad gas. So it had about a half tank.I filled it up and it started running good after a few miles. It had said on the Code Reader about a misfire.I had cleared the misfire code, rescanned and the msifire code was gone. But was replaced with these 2 - 420; CATALYST EFFICENCY BELOW THRESHOLD ( BANK ONE ) - 463; FUEL LEVEL SENSOR A CIRCUIT HIGH INPUT.My wife had brought the car home and said it sounded like the exhaust was making a funny noise. I drove it and it did.Sounded like it wasn't flowing through at full presssure. It seems to sound better, but maybe we are used to it ??? Hope to get al the bugs worked out of it soon.but our luck has always been fix one thing to have 2 more go wrong. Thanks in advance.

The catalyst inefficiency code is picked up by the O2 sensor mounted downstream of the converter. The only function of that sensor is to set the code you got. Basically it needs to read the proper delta between it and the upstream sensor, indicating a proper functioning cat. With all the start/stops misfiring and fuel loading, I'm not surprised you got this code. It should go away after some miles of normal operations. I've seen new vehicles throw this code, it disappears and never comes back. Keep in mind, lots of misfiring will ruin that $$$ catalytic converter.

Joel

Thanks for that info. I cleared the codes day before yesterday.So far the engine light hasn't come back on.I'm still running the fuel pump off another fuse. I have to look more to find a broken wire or whatever else is causing no power to the fuse block for the fuel pump.The car runs great the way it is.But I know if I keep the pump running all of the time it sure won't last as long. In 2 weeks we need to take it on a long trip. Just not enough hours in a day anymore. Thanks again.

It appears we have the same problem. I've got an 05 cobalt ss/sc. I bought it wrecked as i rebuild salvage cars. when I first got it, it started but ran really rough. then it would not start. Eventually It started, but died soon after. I cracked the fuel line near the injectors and no fuel. the car would start if i put a little fuel in the throttle body. I never had heard the fuel pump kick on, never. i read this thread and decied to jump the fuel pump relay no luck. i pulled out the fuse box under the hood. looked it over, plugged it back it and magic, it started. I test drove it, got home and it died. i eventually got it started the next day, but died not long after. putting everything together i bought a new relay for the fuel pump, no luck. I took the cap off the old relay, plugged it in and tripped the relay by hand. magic the fuel pump kicked on but stayed on even if the key was out if the ignition. its like the power to the relay's polarity was reverse. I am guessing that maybe the circuit board that the fuses plug into under the hood is bad. My fix, I found the hot wire to the fuel pump. its the larger grey wire on the far left at the plug in under the rear passenger seat. I spliced into that wire and connected it to a wire in the fuse box near the passenger floor that only turns hot when the key is on. now the fuel pump comes on only when the key is on. I know its not the correct fix, but it works. I have a feeling that the circuit board in the fuse box is bad, but just a guess. if you have any questions email me at clint.shumaker@theschaefergroup.com ill be glad to explain it. if you find the correct solution please inform me.

Haven't had time to get back to this site.The Cobalt has kept me busy. The head gasket went and had it replaced.The factory said the head cannot be serviced.But it had a slight warp.So I had it shaved .015.Put it back together and that part of it is working fine.Had it on the road a week. Wife called and the car wouldn't start when she got to work. So I towed it home.Fuel pump again. Even with a jump wire , no luck. Messed with it for an hour and it fired up. Took the wife to work because I still didn't trust it. Same thing happened to me. A no start. Messed with it again. No luck. Called a friend to take me home and get my truck and tow dolly. Took her about an hour to get there. Tried it once more before we were to go. It fired up. Got it the 15 miles home. I figure there must be a bad wire between the fuse block and fuel pump. I am going to run a hot wire from the fuse block back to the pump harness. This car reminds me of the Chevette my wifes sister gave us years ago. The car was 2 years old. She called it the car from hell. I wanted to pay for it. She said she couldn't take any money for it. Did you ever get a car for free and still feel ripped off ??? It was down more than up. I sold it for the $60.00 I had in the new battery in it. The guy was warned by me what a piece of junk it was. He stuck hundreds into it. Still was junk. He put it where it belonged ... in a Charity Benefit where people paid a dollar to hit it with a sledge hammer. Then it was off to the crusher. If we still didn't owe 2 years on this car that is what I would do with it.:runaround: