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Problem with a coil pack swap

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Old 10-24-2006, 08:53 PM
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Hmm, I see a major problem, are those mounting screws aluminum? If so, that is why you are not starting, because there is no ground. They sure do look aluminum, take them out and go get some correct ones fromt he junkyard. I bet that is your problem.
Old 10-24-2006, 09:40 PM
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Originally Posted by Bonneville94V688
Hmm, I see a major problem, are those mounting screws aluminum? If so, that is why you are not starting, because there is no ground. They sure do look aluminum, take them out and go get some correct ones fromt he junkyard. I bet that is your problem.
They arent aluminum. They steel or zinc whatever that is.



why wouldnt aluminum work if they were? Doesnt aluminum conduct electricity fror a ground? doesnt the ICM get its ground from the bracket itself and not through the bolts? The holes in the coils and ICM that the bolts go through look like they are much bigger than the bolts that fit into threads on the plate.

Anybody know for sure where or how the ICM grounds?

I just checked with a meter and I am getting 12 volts on the first wire in the harness that plugs into the ICM.
Old 10-24-2006, 09:58 PM
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I also checked for spark on the 3 & 5 plug wires and nothing.

I just now noticed on the picture of the manual above, the 3/6 coil pack looks like it came from the 86 to 88 3.8L TYPE II. The order for it is 145263.

I thought this ICM and coil pack was from a 92 and later but if its from a 86 through 88 type II, will it still work?
Old 10-25-2006, 05:51 PM
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A member who has a post in the 92-99 section is having the same problem. He also has checked for power to the ICM & replaced both the ICM & crank sensor. Those three things will normally get you spark.
Is there anyone you can try swapping ICM & coils with?
What condition are the spark plugs in?
Old 10-25-2006, 06:20 PM
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I might have overlooked it in the post, but was the car running before you did the swap. If it was then we need to look at what has changed since. I would look at the ICM. Even if you had one bad coil it would still try to start on the other 4 cylinders.
Old 10-25-2006, 06:24 PM
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Do you have a tach? If the everything up to the coils is working [ICM included], the tach will jump around when cranking [usually about 400RPM]. If something before the ICM is bad [crank sensor, ICM, or wiring], then the tach will not work when cranking. If you don't have a tach, there really isn't an easy way to tell, other than just checking for spark at the plug. You can test coils by checking resistance but i really don't remember how, or what resistance equals bad coil. I'm sure someone knows.

MFB is right... one bad coil won't prevent the car from starting... btw.
Old 10-25-2006, 06:33 PM
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http://www.bonnevilleclub.com/forum/...e=article&k=33

Here is the link in tech info on coil resistances.
Old 10-25-2006, 09:19 PM
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Originally Posted by opensourceguy
Do you have a tach? If the everything up to the coils is working [ICM included], the tach will jump around when cranking [usually about 400RPM]. If something before the ICM is bad [crank sensor, ICM, or wiring], then the tach will not work when cranking. If you don't have a tach, there really isn't an easy way to tell, other than just checking for spark at the plug. You can test coils by checking resistance but i really don't remember how, or what resistance equals bad coil. I'm sure someone knows.

MFB is right... one bad coil won't prevent the car from starting... btw.
Thankis for everyone'* replies, they are all very much appreciated.

I think opensourceguy has hit the nail on the head here. I do have a tach and it is not dancing around like it should.

I first noticed the car acting up when I would drive to the convience store around the corner, (engine wouldnt be hot) and come back out and it would jsut turn over and over and not crank up. I could sit there for a few seconds and try it again, and it would fire right up. It wouldnt do it everytime I turned the car off cold and tried to start it back up, just everyonce in while. Then about a month later, it just would fire up at all.

I thought it was my mag coil pack so I went and bought a new one. It still did not crank up, so I took the new one back and put my old mag back on there.

A mechanic buddy brought over a little diagnostic machine and after we chased down why the service engine light wasnt working and sunsequently put a bulb in the open recepticle :/ , it didnt tell him what was wrong, i presume because we couldnt get it running. The diagnostic machine had an electronic rpm gauge at the top, that he says revs up as the engine turns over...and mine wasnt doing this, so he determined it was the crankshaft position sensor, which we carefully replaced, and still no fixy car. >:(

About this time, we noticed one of the mag coils was hot so I took off the coil pack and noticed the blue gummy sealer that covers the computer stuff was all melted on the ICM. Here is a photo of the melted ICM on the left compared to one from an unknown model. (the harness plug is different and it is a little taller)



The melted ICM wasnt quite this bad, I dug some of the silicon type stuff to see what exactly was in there, since it was obviously broke.

After all this I decided to buy a delco ICM and pack kit from BillBoost and this is where Im at.

Im sorry this is so long and sortof repeats my other thread, but I am trying to give you every detail to pinpoint the problem. I dont know where to look now, so I need help badly.

So to answer your question OSG, no the tach isnt reading anythig while cranking.
I am also gettting 12 volts to the delco ICM when I turn the to the on position.

Sorry for the grammar mistakes. I just got home from a long day at work and its all I can do to make this legible.
Old 10-25-2006, 09:29 PM
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Originally Posted by Technical Ted
A member who has a post in the 92-99 section is having the same problem. He also has checked for power to the ICM & replaced both the ICM & crank sensor. Those three things will normally get you spark.
Is there anyone you can try swapping ICM & coils with?
What condition are the spark plugs in?
Ted, I did not pull a plug out, I just pulled the wire and inserted a spare plug in and then grounded it off while turning the engine over to see if I had a spark. I checked 1, 3, & 5 wires from, the coil packs to see if one of the packs might be bad, but nothing out of any of them.

I will go pull a few plugs and report back in a few mintues.


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