Problem with a coil pack swap
#11
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Originally Posted by Technical Ted
3 & 6 spark at the same time so even if they were reversed the engine would still run.
Check for spark at all three front cylinders. If you're not getting spark from any of them check for 12 volts going to the ICM. The ICM gets power from the pink (some years were pink/black) wire at one end of the wiring harness. The key has to be in the run position while checking for power.
Check for spark at all three front cylinders. If you're not getting spark from any of them check for 12 volts going to the ICM. The ICM gets power from the pink (some years were pink/black) wire at one end of the wiring harness. The key has to be in the run position while checking for power.
It looks like this coil pack may have had a failed coil at one time.... Looks to be a Coil from a Chevy 60*, 3100 or the like... But it will serve the exact same purpose... And both of the plugs as stated will fire at the same time using the waste spark method... So there should be no problem here
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#12
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.
#13
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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.
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.
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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?
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?
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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?
Is there anyone you can try swapping ICM & coils with?
What condition are the spark plugs in?
#16
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.
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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.
MFB is right... one bad coil won't prevent the car from starting... btw.
#18
http://www.bonnevilleclub.com/forum/...e=article&k=33
Here is the link in tech info on coil resistances.
Here is the link in tech info on coil resistances.
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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.
MFB is right... one bad coil won't prevent the car from starting... btw.
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.
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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?
Is there anyone you can try swapping ICM & coils with?
What condition are the spark plugs in?
I will go pull a few plugs and report back in a few mintues.