Random Misfires, Sick Camaro

[blowncamaroz]

OMG, here we go. I have a '97 camaro 3.8 seriesII and this car is driving me insane. I recently replaced the engine with one out of a '96 firebird and it has run great up unitl about two weeks ago. It started off as somewhat of a inconvient power loss during hard accelerations. But now it is on to a full out power loss, stuttering, sputtering, random misfires. This is what I have already done.

1. Replaced all upstream O2's Bosch OE
2. Replaced all plugs, OE AC Delco
3. Replaced all wires, Talor 8.5mm Spiro
4. Replaced all Coil Packs, MSD Twin Tower HV
5. Ran Heat through a new tank of premium.
6. Replaced Fuel Filter
7. Cleaned Air Filter
8. Checked Injectors for Operation.
9. Checked Fuel Press. = 43-46
10.Checked Compression, all within 125-130
11.Checked for valve timing no exhaust suck up.
12.Cleaned intake manifold.
13. Checked fule press. regulator vacuum
14.Clean front of engine with high press. for crank sensor.

15. Ran Codes, Said my MAF was high signal, cleaned and rechecked, good signal. Random Misfires, Ho2 was bad, replaced. AIT was -38, low signal, replaced. And then it had Two Manufacture Codes that I couldnt get at.

So basically thats all I have done so far, now my tanny is slipping alittle because I ran my TC alittle too high on stall last time replaced. I am rebuilding my tranny this weekend with a TCI kit and a B&M Torque Master Con. 2000 stall. But its not going to get me anywhere if the engine isnt working right. So any more ideas and I will be happy to throw more money at this POS.

[jbfirebird22]

all of the past posts have the answer in them. replace the "plate" under the coil packs(ICM)...thats your problem...100% positive

[blowncamaroz]

Sorry, i forgot to add, i had an extra icm and i did switch them. Cleaned very well and put Baking Soda under it for moisture protection. No change, im pretty sure its not the icm, and i dont see my tranny slippin causing this because its a 97, in 98 they went to tcm's which i dont have.

[wildfalcon]

check cat
check icm

plug in autotap and monitor where its missin

[blowncamaroz]

Just put on a full cat back exhaust and replaced cat with catco high-flo 3''x3'' and from cat back its 2 1/2 all the way back. this was done when I replaced all of my Ho2's. Changed the ICM once already have buddy with anoter new one, will try that. And I have put it on a autotap and put it through several runs it comes back with a random misfire code, but the misfires are not registering in the history. Will post on results.

[aalugo2000]

just a side note, when i put a catco 3" on i melted it and got it clogged the first nite out, car BARELY ran at first, then just randomly misfired, i dont like catcos, if you ever get headers get rid of it. even if its not causing the problem.

[blowncamaroz]

Thanx for the info on the catco, i will make sure to keep an eye out for it melting down. Well the problem still exsist. I have gone out and drove around and it seems to be misfiring more around 3000-4000rpm during acceleration. Or when I make a turn and start to accelerate out of it. So basically it does it when the engine is getting put under load. That kinda makes me think its not electrical and possibly something mechanical.

Question: Could a high signal MAF sensor do this?

Maybe a knock sensor picking up alittle to much noise?

[ March 20, 2005, 02:28 PM: Message edited by: blowncamaroz ]

[blowncamaroz]

I got it, so after all this my MAF was freaking out. The signal wire between the MAF and the PCM was bad. It was giving enough signal to fool the PCM, but not enough to get my AIR/FUEL right.


Thank You for all ur help guys, till we post again

[brink]

hey at least all of the things you replaced wont have to be in the future [img]graemlins/banana.gif[/img]

[blowncamaroz]

oh no, it started doing it again.

[3.8L95]

at night open your hood and rev the engine by the trottle body and check to see if you see blue sparks i had the same problem i changed my plugwires plugs coil packs igntion contol modual and o2 sims but i noticed one night at the races my wires were arking out all over the place so i moved all the wires off of the engine and away from everything possible and it runs like a champ

[3.8L95]

it dont usualy start happening until 3000rpm

[dacandystore]

It could be the process module under the coil packs, this was the problem in my buddys 99 before we fixed it. And make sure when you are changing out the coils or pretty much anything electric to put dielectric grease on them, sometimes if you dont it will fry them instantly