Same damn problem...

[WideTrackGP_92]

Well I just dumped $1200 into this piece of shit engine and all of a sudden it's missfiring AGAIN!!!!!!!!! Here's what I had done...

Rebuilt and flowmatched injectors
Thermostat/gasket
Power Steering pump
PCV valve
Fuel regulator line
Brake booster hose
Power steering return line
PCV hose
Lower intake manifold gasket
Valve cover gaskets
GM Syncromesh fluid

and a few other stuff that doesn't have anything to do with the motor.

Now, I did the same thing I did before when it was missfiring before I got all this work done and I started the car and removed the plug wires while running to see which cylinder(s) were not firing, and the front middle wasn't firing and either the rear pass. side or middle wasn't firing either. Same fucking thing that happened before I dumped money into it. And I just went downstairs to start it and it's running fine again. What the fuck?!?! Could it be the coils or something? I'm getting sick of this crap...

[55trucker]

You're misfiring on 1,3 & 4....What condition are the plug wires and the plugs in? Is there any moisture down inside the spark plug cavity or in the boots that can cause an arc situation?

[WideTrackGP_92]

Well I said the rear misfire is EITHER the pass. side cylinder or the middle cylinder. The plugs and wires are brand spanking new...less than 100 miles on them. All plugs and wires are AC Delco, so they aren't cheap crap.

[bszopi]

1 & 4 share a coil, so it very well could be a coil pack going bad. The are intermittent failures sometimes. I would replace that coil and see what it does. OR, swap 2 of the coils around and see if the misfire follows the coil.

[3400-95-Modified]

Your mad that you just spent money on the car and its "still missfiring" yet all the parts you replaced do not cure a miss fire... except maybe cleaining the injectors.

I would have the ICM checked and Ohm the coil packs and I'm sure you'll find the issue then.

[WideTrackGP_92]

Well at first we assumed that the misfire was caused by bad valve cover gaskets leading to the plugs being doused with oil, but apparently that was not the case. I just bought all 3 coil packs from Advance Auto Parts (was OE cheapies, not AC Delcos) for $25 per coil, so I said what the hell. They didn't have any AC's in stock anyways. So I'm going to search to see what the best way of getting to those coils are and replace them all. Then if it still does it, then I'm sure it's a bad ICM. I hope that isn't the case though...those damn things are expensive!

[SappySE107]

Junkyard used ICM and coils. I wouldn't buy new parts just to test for a problem. ICM is easier to replace at the same time since the coils mount to it. Ebay has them cheap too. Any 2.8, 3.1, 3100, 3400, 3.4 DOHC set will work (all DIS FWD that is).

[3400-95-Modified]

I might have a few spare ICM's if you want one. They the same as a 3x00 one?

[SappySE107]

Yes, the same thing.

[WideTrackGP_92]

Yeah, that would be cool! My brother is gonna come up tomorrow and take a look at it. If we get the coils in and it doesn't fix the problem, I'll let you know. Thanks bud!

[RedZMonte]

you could try swapping a few coils around and see if the miss follows the coil.... That is a free check. but make sure the coil you swap is good lol swaping 2 bad coils wouldnt tell you anything lol.

[3400-95-Modified]

I'll find one in the AM, I think I know where one is... I hope lol

[WideTrackGP_92]

Well I bought 3 new coils, so I'm just gonna replace 'em all. If that doesn't work, that means it's most likely the ICM, in which the gentleman with the bitchin Beretta kindly notified me that he may have some laying around to sell one to me.

[WideTrackGP_92]

I actually just went on Advance Auto Parts website and they have an ICM that is only $92 and it's a lifetime warranty, whereas the AC Delco is $250 and has a 1 year warranty. So if it's the ICM, I'm definitely going with the one at Advance! Thanks though for offering to sell one of yours.

[Maverick H1L]

If the Advance/AutoZone lifetime DIS modules are anything like the distributor type modules, you'll end up replacing the ICM at least twice as often. I've gone through 2 of them in the last 2 years, and I always make sure to clean everything really good and put heat sink grease (not that cheap crap you get in the box, the good stuff for PCs) on the bottom of the module to help with heat conduction. My AC/Delco lasted approximately 3 years, and that was put on when I found out that I couldn't set the time with the Wells module that was there when I bought the car.

Put AC/Delco on there... Your engine will like you better.

:edit: BTW, check eBay... There's usually some good prices for OEM on there.