00 S10 2.2 won't start

Starting this thread over because I don't think it's a fuel pressure issue. It always starts great on the first start of the day. When I get in after being at work all day, it cranks and almost starts but won't quite catch and run. It's still at work as I writhe this thread. I've checked fuel pressure and it was good. Fuel regulator test was good. I sprayed ether in the throttle body when cranking and no difference. I went through other checks in my previous thread titled '00 S10 2.2 fuel press check? The truck sat in the garage for 2 weeks and started every time whether it was warm or not. I needed it today so I trusted it to take me to work. The wife has come to pick me up twice now in 2 weeks. So far I've replaced both O2 sensors. I had a SES light for the aft sensor that's gone now since replacing it. The engine was replaced 3K ago and runs great when it runs. The entire exhaust was rusted out so I ran a straight pipe W/O the CAT to a muffler. It has a header and CAI. I think its a sensor but I'm not sure how to check them. MAP, MAF look good and are clean. Can I ohm them out? What should the values be? Will the TPS cause this? Or the water temp sensor? Is there a crank position sensor that could be throwing off my timing? The wife is taking me to work at 5:30 AM (she's happy) and it will start right up. She'll bring ut home and park it again so I'll check it when I get home. If I catch it not starting at home I can check spark.

what is the year>?

Do you have a Security light on?? The cat will mess with the back pressure. cram something in the tail pipe when it wont start and give it a little more back pressure. see if anything happens? Obvious don't leave it in there.

You need to start checking on the ignition system. Sounds like you've verified that the fuel system is functioning properly. Check the coil and the ignition module (bolted onto the coil). Some autoparts stores can test the ignition module for you. Next time the engine won't start, pull a spark plug boot off and lay (don't hold) it next to the engine by a good ground (and away from flammable things like the gas lines and the battery), crank the engine and see if the spark jumps from inside the boot to the body/engine. If no spark then it could be a bad coil, ignition module, crank sensor, or cam sensor.

Thanks for getting back on this. It's a 2000 year Extreme. Would the CAT being off not show up for 3200 miles? If I can get it to not start I'll try several things like plugging the tail pipe and looking at the spark but it never happens at home or in a place I can try things like that. There is no security light on and when it's not starting, it will kick just enough to make you think it's starting but it don't. I pulled the coil packs and they ohmed out OK. I replaced the crank sensor, water temp sensor, and air inlet sensor last week. I don't think it helped because yesterday I drove 2 miles and shut it off for about 45 minutes and it cranked about 10 seconds before finally catching on. I wasn't at home so I didn't push my luck. Of course when I got home and left it for 2 hours and tried it, the damned thing started, not on the first revolution but it started. I've read the 2000 2.2 didn't have a cam sensor. If it does I'll change it. I haven't changed the MAP sensor yet because it's a little more expensive. I can get one from a friend though if it'a a possibility.

Hmm, lotta money just changing parts how about some diagnostics, when it won't start check for spark and/or spray starting fluid into the intake if it pops it's a fuel issue, if not no spark.

Agreed. Stop changing parts and start troubleshooting. All those things you just changed did not need to be changed. Don't change the MAP sensor, it has nothing to do with your problem, and don't worry about the CAT either. If I were you I would spend my time looking at the ignition system. Plugs, wires, coil packs, ignition module, and all connections between. Don't just replace, inspect them. Look for bad connections and broken wires, places for water to get into and cause problems. Take the ignition module off the truck and get it tested. Your 2.2L definitely has a cam sensor. The Pontiac Sunfire and Chevy Cavalier both use the same engine, try searching in their forums as well. Oh, what codes are you getting?

I did shoot starter fluid at it the last time and it made no difference. I should have checked the spark at that time when I had an assistant to crank but didn't. It does have some spark because it will almost catch but not so it's not a "no spark" condition. As for a lotta money, all 3 sensors totaled $36. My diagnostics so far have been: Fuel system pressure check with tester from Autozone. Read codes at Oreiley's and got rear O2 sensor code and replaced it. No codes now. Pulled coil packs to check ohm readings cold, then hot (cooked in the oven at 200 for 45 minutes), ohms checked good. I did check the spark a while back and got a good white spark but that was at a time that it would start with a little extra cranking but not as quick as it does on first start of the day. The plugs and wires are new and this happens in dry conditions. It runs too good when it does start to be a bad connection or broken wire. Where can I get the ignition module tested? Thats something I haven't looked at yet and I do think it's an ignition issue. Can I ohm it out?

If it won't start with starting fluid then you have no or insufficent spark or improperly timed spark. A bad crank sensor or weak connections to the icm, could cause erratic no start.

I changed the crank sensor for $9.99 last week. I went for that because when I changed the engine out, I pulled the old one from the last engine and it was hard to pull out. Thought maybe I cracked it without knowing it. The fact that it never, and I mean never faults when it's cold soaked over night or longer leads me to believe it is temperature related and if the ICM has circuitry in it that may open from the heat off the block, I like the chances of it being my culprit. Of course I'll look at the connections when I pull it but if I can find one from Craig's list cheap, I'll swap it out. Rather expensive to get new. I'll check the Haynes manual for any testing I can do. I there are values to check for, I'll check it cold and hot. I think we're closing in on it. Thanks for getting back to me.

I finally have the no start condition. I pulled the coils and checked for power to the ICM and trigger input to the coils. I had battery volts to the ICM and the same to the top post on one coil position and the bottom post on the other. Cranked engine with no change, steady light with test light grounded to chassis on top and bottom posts nothing on 2nd an 3rd posts. Later this afternoon I went back to swap ICMs but found I had 2.3 volts to the ICM. The fuses are good. I've been working through the wheel well and checked all connections I can reach plus the engine harness. This may have been my problem all along bot now I need to find why I lost power. Any ideas??

I hope we're not getting bored of my post. I'm getting 2.3 volts to the ignition control module (ICM). I go to the PCM and get 12 volts in and 2.3 volts out. I was getting 12 volts to the ICM when I first experienced the no start but it dropped to 2.3 during my exploratory. Now I'm stuck at 2.3 volts. Could the Security system be knocking the volts back? If I get another PCM with the same part number will it need to be programmed? In the beginning of all this, the truck would intermittently not start after the drive to work. It would always start in the morning great and run great but on two occaissions it would crank but not start after work. Go back through my trox threads to get more on the story if you need to, getting tired of re-typing the same thing over and over.

Well I took autojoe's suggestion from several replies back and have been putting the gas pedal to the floor to start after the first start of the day. THIS WORKS...I know I haven't fixed anything and there is something causing this hard to start condition in the afternoons but I've been driving the truck to work for 2 weeks now and it has started every time. There have been a couple times I just held the pedal half way and it didn't start as well. If I hold it all the way to the floor, it cranks maybe 2 rotations and fires up strong, (no sputtering like it did when I left the pedal alone) I'm thinking the computer is not resetting or setting for the warm start condition. Don't know if this is a timer or temp issue but hey, it starts. I've tried to duplicate the no start at home to see if I can get into the no start and back out by putting the pedal down but it hasn't "not started" for me yet.

It's been a month and a half and the truck has never failed me in that time. Hold the pedal wide open and it fires right up. I have left the pedal alone and it will almost start but it struggles to catch. I'm content with putting my foot tot the floor to start. Runs great at all times otherwise.

It's been a month and a half and the truck has never failed me in that time. Hold the pedal wide open and it fires right up. I have left the pedal alone and it will almost start but it struggles to catch. I'm content with putting my foot tot the floor to start. Runs great at all times otherwise.

since it starts with the throttle open you must have leaking injector[s]. try some injector cleaner with a couple of oz. of marvel mystery oil to the fuel. see if the starting improves over a few days of use.

Tried the Lucas injector cleaner on a 1/4 tank of gas, drove 20 miles, didn't change anything. It still starts good with the pedal to the metal.

I have the same truck 2000 2.2 s10 with the same problem, It starts fine cold but if it sit for maybe 20 min after its warm you have to crank it for a time before it starts, put foot to floor while cranking it fires up, My truck is lagging a bit power wise, Fuel press at rail at idle is 35lbs but it goes up to 40 when you rev it up a bit, around 40 psi not running, I did not see or smell gas at the reg vac hose, The pump got real noisy the other day when it was VERY low on fuel, banged on bottom of tank and it wasent so loud, filled up with gas now i dont here it, I replaced filter, no change, I had the head off the truck for head gasket and burnt valve, I bought it that way, I think I will take a look at the plugs next,(there new) to see if i can find a wet one, If i dont turn the key and let the line prime it wont start right away, if you prime it with the key it fires up Quick, I think it has to be the pump or injector or both, I will let you no if i get anyware with it, I also tried lucas and it did nothing.

I to have the same truck also. Just so you know holding the throttle wide open is a flood over ride which means your truck is flooded when warm caused by a bad fuel injector. And I am having a problem as well maybe you guys can help. My ecm is throwing a code for camshaft positioning sensor and I do not have one at all looked all over the pass side completey. Does anyone know if some of the 2.2 were made with out a cam sensor in them?

my best guess would be the ignition control sensor... if cranks when you give it plenty of gas, and continues to run w/o any problems we know that its not a spark or fuel problem. that would leave something like, sensors or relays to look at. i would start with the ignition control sensor and if nothing changes, try the throttle positioning sensor. good luck