2.8 won't run under load

[Legion]

Hello to all. First time posting here. I have an '89 grand prix with the 2.8 engine in it. Yesterday, I was on my way to work when, as I tried to pull away from a stop, the engine gave me no power at all. It was like I wasn't pushing the pedal more than 1/4 of an inch down, no matter how far I floored it. That persisted all the way to work, where I shut it off. I work at a Dodge dealer, so I had one of the foremen at work hook up a snapon scanner to it, and check it out. It started and ran at idle, and he said that there was nothing wrong that the scanner could see. About half an hour after that, I started it to go home, and the no power was still there. I almost made it to the other side of the parking lot, and it died. Got it to start again, but it wouldn't idle more than about 400-500 RPM, and I could smell gas everywhere. The fuel pump, fuel filter, spark plugs, plug wires, and one of the coil packs are only about a month or so old. I took the cat out a while ago, after it started glowing red everytime I drove the car. I checked for an O2 sensor, didn't find one, and since I don't have emissions where I live, I just took it out and put in a straight pipe. From all this, I am thinking that the ICM and/or the other 2 coil packs are bad, but I could really use some input here, I feel like I am just flailing around in the dark. Thanks in advance.

[geoffinbc]

Well check plugs and wires.

There is an O2 sensor it is in the rear manifold. You might wana replace that it could be a cause. Another sensor to check is the ECT sensor. See if the temperature the ECM sees is accurate.

[Legion]

Ah. Didn't think to check in the manifold. Thanks for that. The wires all are fine. Will pull the plugs when I install the ICM to check on that too.

[Juglenaut]

Check your fuel pump, regulator, vac lines.

I not saying it is 100%, but if the ICM fails or the coils a persistant fuel smell comes out of the muffler and possiblly will throw a ICM code, o2, or MAP or all codes. Called a dead wet fire, or wet and dead, over fuel compensation where unspent fuel is expelled into the cat. dead wet fire> partial burn. Wet and dead, no spark and wetted with fuel.

No fuel is opposite dry fire or dry dead fire, Dry fire>when it fires but no fuel to burn. Dry Dead fire> doesn't fire and no fuel.

[Legion]

Well, got an ICM swapped in from a 3.1, was told that it wouldn't be a problem, as the 3.1 and 2.8 were basically the same engine, with the exception of crank and rods. There was a lot of fuel smell from the exhaust, but not now. The problem that I'm having now is that since I did the swap, I'm getting backfiring, really hard to start, and it dies at idle. It will run if I keep the pedal in a little once it is started, but it won't stay there. I was told that the IAC might be fouled, so I'm going to put in a fresh one. Also might have messed up the wire order when I was swapping in the ICM. Anyone know the cylinder order? Maybe a picture somewhere? Feel stupid here, but I lost my haynes, and the local parts store is out of my edition right now. Any other ideas on this one? Thanks in advance.

[bszopi]

That will definately cause problems like you are describing if the wires are swapped.

[Legion]

Awesome! Exactly what I was looking for. I'll check the wire routing on my lunch break, and let you know. Thanks again for the pic.

[Legion]

Sorry about the delay on this, but that diagram must have been for a different year or something, it wouldn't even start the engine. I had one of the techs here check Alldata for another one, and it worked. Worked like a champ! The car is running better than it has in years. Thanks to everyone who helped on this one, I really appreciate it. Just in case anyone is interested, the cylinder numbering and coil numbering for an '89 Pontiac Grand Prix with the 2.8 V6 is here:

Engine

(1)(3)(5)
(2)(4)(6)

-Front of car-

Coil Packs

1 4 6 3 2 5
-[]- -[]- -[]-

[geoffinbc]

You have coil packs at the front of the engine thats why. The pic Brad posted was for the coil packs mounted on the top of the engine.

All you have to do is turn the part numbering the coil packs up-side-down.