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-   -   02 Boneville Mis-fire (fixed) (https://www.gmforum.com/pontiac-168/02-boneville-mis-fire-fixed-298929/)

WS-13 04-18-2011 10:25 PM

Update:

Okay...so I checked all the coils using the write up posted in the link above. They all checked out fine and were well within the range they were suppose to be as specified in the write up. I also changed all the plugs just to make sure that wasn't the problem either. Still no change and the car is running just as bad as it was before. I feels like it only running on 3 or 4 cylinders and could barley pull itself up my driveway.

Ideas?

Is it posssible that my ICM is bad? I figured if the ICM was the culprit then the motor wouldn't even crank over.

Danthurs 04-18-2011 10:29 PM

When you pulled the plugs, did any of them look different?

WS-13 04-18-2011 11:05 PM


Originally Posted by Danthurs (Post 1521070)
When you pulled the plugs, did any of them look different?

They all looked pretty much the same except one was darker and looked wet from fuel.

Here are a couple pictures:

http://i479.photobucket.com/albums/r...A/102_0086.jpg
http://i479.photobucket.com/albums/r...A/102_0087.jpg

Danthurs 04-18-2011 11:08 PM

And what cylinder come from, because that's your problem. It's not firing right. Check that plug wire.

WS-13 04-18-2011 11:37 PM


Originally Posted by Danthurs (Post 1521086)
And what cylinder come from, because that's your problem. It's not firing right. Check that plug wire.

It came from #3. I did check all the plug wires and they looked fine. I just replaced them less than 5k miles ago. The car is definately missing on more than one cylinder. It can barley keep itself running especially when you put it in gear. :confused:

ymmot04 04-19-2011 12:09 AM

You should be able to pull a code and tell which cylinders are misfring. When you figure that out, try swapping two of the coil packs and see if the problem follows the coil pack. You can also test the coil packs, Dan has a writeup on how to do this.

I am a fan of Iridium spark plugs, they cost a little more, but last much longer. Won't work in the SC'd cars, but hold up just find in an SLE. IIRC, your car may even call for Iridium plugs.

While you are at it, check your wires and see if any look damaged. I think I just bought my second set of Bosch wires with a lifetime warranty. I figure for $25 they are worth it, especially if your wires have never been changed and are starting to look worn.

SignOfZeta 04-19-2011 02:56 AM

Second on the plugs. It's not that Bosch plugs are terrible, they just weren't built to withstand a waste-spark engine, sort of like hammering a nail with your toolbox.

Check that spark wire, too. #3 on my last set of wires got oiled, burned, and whacked by the fan before it finally started misfiring. There was a flat white spot on it. (Still not quite sure how that all happened.)

WS-13 04-19-2011 09:49 PM

Final Update:

So after testing the coils, checking the wires and swapping the Bosch plugs for NGK's and still having the misfire problem...I decided to pull the ICM and take it down to have it tested at Auto Zone. The ICM tested bad so I bought a new one for $136.

After installing the new ICM the misfire was completely gone and the car started and ran smoother than it ever had before. I cleard the SES light with my scanner and it never returned.

I thought that it was unusual thet the ICM would cause such a misfire because everything I read said that the car normally wouldn't start (or run) with a faulty ICM. This of course was not the case in my situation.

Anyway, thanks to those who posted up trying to diagnose my problem over the internet. I really appreciate it! There was a lot of helpful info that led me in the right direction.

Billy

Danthurs 04-19-2011 10:04 PM

Generally a bad ICM will cause other problems. However, if you have bad terminals that will cause problems with that coil, and it looks like that was the case here. Good deal. I'll mark this thread as fixed.


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