grand am 3.5 swap problems

[gsanche7]

about .35

[mfuller]

Are you sure you didn't mess up the order of the spark plug wires?
That could cause a nasty backfiring.

[2kSCT]

Mixed up wires would cause a very rough idle, one that would be noticeable before backfiring at 4k rpm. So I'm guessing the closer the better is the case when it comes to the trigger kit? Mine seems far away but voltage readings done at school today showed about .5v from the sensor while cranking.

[AaronGTR]

It definitely sounds like a crank sensor to me... for both you guys. You don't want back pressure in the exhaust (back pressure is the enemy) and neither one of you have large enough exhaust tubing with those mods that it would cause a really significant loss of low end torque. It also wouldn't account for loss of power or any backfiring/misfiring above 3000 rpm.

The 24x crank sensor actually only controls timing up to 1600 rpm. At 1650 and above the ignition control module converts the 7x crank signal to a 3x reference signal for the PCM for timing control. According to my manual though, the 7x sensor is the most critical. If that is not present, the engine won't run. If it is present, but it's not sync'd up with the cam sensor signal, then it will run at a default low timing that is built into the ICM. If that's the case though you should get a DTC code P1351.

I would say the problem is probably either with the coils, the ICM itself, or the 7x sensor. You might need to check and adjust the trigger wheel and/or the sensor mounting, or even replace the sensor. If you have a scanner/tuner you should be able to see any codes present and see if the timing is bouncing around like normal above 1600rpm or if it's running at default.

[2kSCT]

Well the coils I have are the msd ones and I also have the 8.5mm wires. I started testing resistance in the coils at school today and found that one of the posts on the far right tower was more brown than all the other coils' posts. Probably unrelated... Ethos scanner and tech 2 both show no new codes and not even a misfire code.

[AaronGTR]

Try swapping your stock coils back in if you still have them and see what that does. I had two MSD coils go bad on me. It may have been a problem related to the coil pack adapters for the DIS-4 ignition box I was using at the time, but it also may have just been bad coils. Anyway it's worth a try and eliminates one more possibility if that doesn't fix the problem.

[HOYS]

Check spark on each cylinder and make sure your wires are on the proper cylinder.

Also, I might be in Riverside within a few months if your still having problems, Moreno Valley to be specific...

[gsanche7]

If the cables were messed up i would defintetly get a misfire code but i dont get on on any scanner.

[gsanche7]

Originally Posted by AaronGTR

Try swapping your stock coils back in if you still have them and see what that does. I had two MSD coils go bad on me. It may have been a problem related to the coil pack adapters for the DIS-4 ignition box I was using at the time, but it also may have just been bad coils. Anyway it's worth a try and eliminates one more possibility if that doesn't fix the problem.

And i am using the stock coils but still having the same problem . i am curious if this code has anything to do with the backfiring problem (P0620) it comes up because of my bad alternator

[locoman99]

Originally Posted by gsanche7

And i am using the stock coils but still having the same problem . i am curious if this code has anything to do with the backfiring problem (P0620) it comes up because of my bad alternator

Wait a second...u know u have a bad alt? Change it. A failing alt can make your ignition do crazy things

[gsanche7]

yeah i went to go get one today and amma change it tomarrow.

[2kSCT]

I don't have the stockers any more.there's a 01 gt at the j/y that has some on it, chances are they're still good . Where is the ICM exactly?

[chris_gt_74]

Originally Posted by 2kSCT

I don't have the stockers any more.there's a 01 gt at the j/y that has some on it, chances are they're still good . Where is the ICM exactly?

I always thought it was the plate the coil packs plug into.

[2kSCT]

That would make since... But it's just a plate and there's not really anything "module" about it haha. Well, when I was checking the coils, I noticed one prong was kinda angled to the left, outward if you will. This is interesting because that also happens to be the same coil that has the darkened brass post. Could the angles prong be causing a bad connection making the current arch which browned the post and possibly damaged the plug wire?

[gsanche7]

to see the icm remove the ignition coils and the icm is the one that ur coils are plugged into.

[gsanche7]

which junk yard ? u saw the icm and coils at i call dibs jk

[2kSCT]

The off milliken in Ontario. It's like 4 blocks from my school so it's not hard to stop by there on the way home. Is an alero ICM and coil pack the same as ours?

[gsanche7]

i have been to that one and as long as it is a 3100 or 3400 it should be the same

[2kSCT]

I thought so. Today I was there and got a front right quarter panel for $50. Scooooore haha

[AaronGTR]

Originally Posted by 2kSCT

That would make since... But it's just a plate and there's not really anything "module" about it haha. Well, when I was checking the coils, I noticed one prong was kinda angled to the left, outward if you will. This is interesting because that also happens to be the same coil that has the darkened brass post. Could the angles prong be causing a bad connection making the current arch which browned the post and possibly damaged the plug wire?

It might not look like it, but it is in fact a module. It has three harness plugs on it, and connectors for the three coils. The circuitry is hidden inside. And yes, any problem or anything out of the ordinary with the ICM could be causing your problem.