misfire fix

[astroglyph]

hey guys, i have a pretty bad misfire goin on, who doesnt? anyways, its really getting old, my 98 3.8 camaro would start up fine until it started to get warm, then it would throw a code 0303, cylinder 3 misfire, and its really bad, the car gets no power when its misfires, its so bad i havent been able to drive it for a few months now, and had to get a beater car till i fix this one, that was when the car was bone stock, now the car has a header back 3" exhaust, (pacesetters, catco, and a tsp rumbler), brand new o2 sensors, msd super conductor wires, accel u groove plugs, optima red top battery, and a new alternator, and now, although not as bad its still very apparent, and its still throwing the 0303 code, so what do you guys think now, im thinking coils(im gonna buy an msd set), ICM, or injectors maybe, i have no idea anymore, its really getting frustrating, what should i pick up first, the ICM, or the coils, any reassurance or help you guys could give me would be great, thanks guys.

[terminaldegree]

One idea to isolate a problem with the coils-

Start the car and run it until the problem starts to happen.
Turn off the car - remove the #3 spark plug wire from the coil.
If the car DOESN'T run worse after you do that, replace that coil.

Also, some cars are finnicky about needing to use OEM spark plugs [ac delcos or the NGK equivalents]. I don't know what the heck those accel things are...

You seem to be on the right track.

[98DC]

Anyone care to share their trick on removing the #3 wire from the plug. The rest of them are pretty easy. Number 3 kicks my a$$ everytime

[Nikos95]

I havn't looked on a 3.8 but on my 3.4 i reach my arm down from infront of the ac compressor and back to get my wrench in there.

[astroglyph]

alright, i swapped the first and second coils, and its still throwing the reliable old 0303 code, and misfiring badly, so what now, i only have 75k miles on it, and most people tell me the the injector wouldnt have gone yet, so what do you guys think, icm or an injector?

[1996F-bird]

WE had a bad misfire with my 3.8L Firebird....and we replaced the O2's, plugs, and wires. Finally took it to dealer, and they replaced the fuel injectors, and it runs fine

[98DC]

Originally posted by astroglyph:
alright, i swapped the first and second coils, and its still throwing the reliable old 0303 code, and misfiring badly, so what now, i only have 75k miles on it, and most people tell me the the injector wouldnt have gone yet, so what do you guys think, icm or an injector?

Mine is doing the same thing, I replaced the coil packs, plugs, wires and ICM. It didn't do anything but make my pocket feel $600 lighter. If I end up taking it to a dealer I'll let you know what happened.

[98DC]

Originally posted by 1996F-bird:
WE had a bad misfire with my 3.8L Firebird....and we replaced the O2's, plugs, and wires. Finally took it to dealer, and they replaced the fuel injectors, and it runs fine

What did that set you back?

[Hada79z28]

Hey, i have the same problem too... I had a misfire just like you, but in cyl. 6. I had the plug and wire fixed, but its doing it again... WITHOUT ANY CODE!!! I only have 39K on my 98. What in the world can it be??? If any of you know. Astro hows it going for you?

[astroglyph]

hey 98DC, have you tried fuel injectors too? im gonna swap fuel injectors tomorrow and see if the misfire shows up on another cylinder, if its not that and its not the ICM, i dont really know where else to go besides taking the motor apart. When i start my car its not so bad, but when it gets warm it starts getting pretty bad, which doesnt make sense to me. Theres no way im gonna pay dealership prices to fix this, im gonna end up selling it if this doesnt fix it.

[98DC]

I haven't tried the injectors, I'm just going to byte the bullet and take it in to the dealer. I have waisted $600.00 trying to fix it my self, It would have been cheaper in the long run just to take it in. I need to sell it to get something bigger, it just needs to be fixed.

[astroglyph]

well, i just ordered an icm, hopefully it fixes my problems, and hey, 98DC keep us posted, thanks for everyones help, i'll let you guys know if it was the icm or not

[astroglyph]

well guys, got the ICM, and as usual, no luck at all, now i gotta run the ICM back to autozone and get my $120 back, ugh, friday i'm gonna have a buddy follow me as my car barely makes it to a local shop, hopefully he can figure something out, do you guys have anymore suggestions? I'm just clueless and more frustrated now, thanks.

[98DC]

Let me know. I haven't taken it in yet. I need to save up for this one.

[slow6]

a bad PCM (computer) could really make a misfire?
thats crazy