1985 Grand Am

[Tech II]

If you now have spark, and this thing is running rough, need to know if it's timing or fuel.......disconnect the injector.......have someone crank the car, and spray carb cleaner into the intake......if it idles ok, then it's a fuel delivery problem......if it still runs rough, then we could have a timing problem, spark problem, compression problem, etc.

Mark the base of the distributor shaft and where it enters the block....then loosen the hold down bolt.....re install injector harness.....turn distributor slightly clockwise, and start car.....if no improvement, try counterclockwise.....if no improvement, move distributor back to the marks you made....recheck that your wires from the distributor cap are going to the correct plug......check rotor and inside of cap for arcing at the contacts.....don't forget to tighten hold down bolt.....

[jayrider75]

Ok ,checked the distributor cap and one of the poles came out with the spark plug wire. It's not super loose, but I checked the egr. and made a quick gasket because I never put a new one on yet,and I got her running pretty good! So now the timing I can find pretty much the sweet spot , but I cant get the mark close to the timing mark, the closes I was able to get with it running good was about 3 inches away,and yes I did have the check engine plug in. Could it be possible to be off a tooth and it still run?

[Tech II]

Man, you are asking me to remember something 30 years ago.....

Is the emission label still on the radiator support? I think it tells you how to do base timing......wasn't there a harness to disconnect? Think it was suppose to be something like 8 degrees BTDC with a timing light?

I would be replacing that cap and rotor......and wires if old....

[jayrider75]

OK, I was trying to time it with the #1 wire,insted of the coil so I switched iit ,but the timing mark doesn't seem to be much different , far from the timing marker all together. I have the ALDL connected like it supposed to for timing,and I got it running alright,but the second I disconnect it ,it dies! I did runn it down the street though couldn't help myself! So I'm still wondering if 1 tooth on the timing could be why it's off..or would it even run?

[Tech II]

Very hard to check the timing of this engine.......I believe it has two meshed gears, that it doesn't have a timing chain......getting that timing cover off is a bear......it is sealed with RTV......and usually when attempting to remove the cover, you bend it all to crap, and you have to, more or less, get a new one.....

Sealing the new one is not easy.....have seen them leak afterwards if not properly done.......tend to doubt it would jump one tooth.....when the gear goes, you'll definitely know.....so, doing this is a last resort......

So you put the car in base timing, by grounding A to B in the ALDL?

I thought the timing light had to be hooked up to #1 wire......been a long time since I did one of these, and the memory is a little foggy on this.....do you have a manual or info with specific instructions on timing this engine?

Do you know if the Distributor was ever pulled on this engine?

[jayrider75]

Yes I have the timing gears not a chain ,and I wasn't thinking about the gears on the timing but if I installed the distributor 1 tooth off,and I bought the engine used ,but used my distributor. I thought it was supposed to time it @ the #1 too but I looked it up in the manual and it says the coil..but I'll check 2wice.Yea that would be the last think I want to do..take that timing cover off.

[jayrider75]

Alright the car is purring good with the ALDL connected . Revs good smooth , I even drove it up the street just fine , but when I unplug the ALDL it chokes and sputters then dies.I tried to send a video, but I don't think it was possible.Better to see and hear than just words sometimes.

[Tech II]

So, what you are saying is, it runs ok in base mode, but when the computer takes over, it doesn't......you have checked for codes?

Could be a bad ICM or computer......

[jayrider75]

Well i'm not sure if codes will even show up in base mode will it?my tags are expired so going on main roads cant happen,and i need to go a few miles and get up to @ least 45 right?as far as bad ecm..i hope not i had to order this one from southern cali!no codes for bad ecm show up.EVEN STILL WHILE IT IS RUNNING IN BASE THE TIMING IS STILL OFF BY A FAR.I'VE ADJUSTED THE HELL OUT OF IT , CHECKED TDC ,MARKS LINE UP ON THE PULLEY DIST. SEEMS TO BE LINED UP TO WHERE #1 IS..

[Tech II]

Well i'm not sure if codes will even show up in base mode will it?

I don't think it will run diagnostics in base mode....not good to run vehicle this way, anyway......seen an exhaust manifold go "cherry"....

my tags are expired so going on main roads cant happen,and i need to go a few miles and get up to @ least 45 right?

You can't run a drive cycle in base mode....

as far as bad ecm..i hope not i had to order this one from southern cali!no codes for bad ecm show up.

Did you get a new , updated PROM?

EVEN STILL WHILE IT IS RUNNING IN BASE THE TIMING IS STILL OFF BY A FAR.I'VE ADJUSTED THE HELL OUT OF IT , CHECKED TDC ,MARKS LINE UP ON THE PULLEY DIST. SEEMS TO BE LINED UP TO WHERE #1 IS..


The Pulley mark should be on "zero".....during compression......and the rotor should be spot on the #1 coil terminal.....

[jayrider75]

I bought the ecm used out of san diego so it has the matching service # came out of a stick shift 2.5L, 85'..so as far as getting the car to run on it's own ,-without base connected- it is barely able to have an idle i would guess it was probably 300rpm?-I've gone the full range from left to right and inbetween on the dist-.Then dies fairly quick , but when i hook the base back up I have to move the disrtibutor again. I haven't mentioned this yet because i thought maybe there was no significance but there are two different wires coming from the driver side that are not hooked up 1 i found a matching color that goes back towards the ecm, the other not so sure.So I will go thru the tdc again..I know we talked about tdc on #1 or coil, my manual says coil,and like you've said you thought it was #1 and so did I,the strange thing to me is that as I test the timing that marker stays in the same exact range isn't that strange?and so no more running the car on base mode? That puts me back a little

[Tech II]

It's ok to run in base mode for test purposes, but you should not be driving it on the road that way....

Let's get back to basics.....have you done a compression test on all cylinders?

Have you checked for a healthy spark at the end of each wire with a spark tester?

If yes to both, and you have it timed by sight......pulley mark on zero(stroke on compression).......rotor lined up with #1 terminal......wires correctly on the distributor.....in a clockwise motion, the wires should be 1, then 3, then 4, then 2.......



Disconnect injector.......base timing.....have someone crank car....spray carb cleaner into throttle body....once started, adjust spray to see if car idles ok......if it does, stop.....get out of base timing......start car again, and spray carb cleaner into throttle body....adjust spray for a smooth idle......if you can achieve this, then the problem is fuel delivery......fuel pressure should be 9-13psi......if pressure is ok, then could have a bad injector or the ECM is not pulsing the injector correctly......the ECM could be bad, the PROM could be bad(did you transfer the PROM from the old ECM into the "new" ECM?), or there is a sensor that is causing the problem(would need a scan tool to read data).......

[jayrider75]

Alright I'll get on that..but about the newer ecm i bought ,well the original ecm I thought to be bad ,so I purchased a new one from the store to then put my prom into, found out aftre that I was given a old used returned ecm, so I exchanged that 1 for a NEW one but when I went to install my prom it wouldn't take got the 15 code i think it was .. so I went back to my original ecm and had the same code come up , so in turn i'm sure my prom was fried from th e bad ecm I bought from the store . Thats why i found the ecm I bought now.Also, my comprssion checher went bad on me a few years ago , but the engine I bought used and was pressure tested, I know thats no assurance .

[jayrider75]

so i just got done with unplugging the fuel injector and spraying carb cleaner and it started to run a little , then I reconnected the inj. with base disconnected and it ran fairly but rpm,s were low..very, but it was running on it's own ,,now years ago upon desperation I had played with the" idle stop screw"is that a possible thing to play with? THat would raise or lower the rpm's right?Though I'm not sure if thats agood move.

[Tech II]

answers to post #27?