I recently bought an 86 Buick Electra Park Avenue with the SFI 3.8 Buick V6 from my parents to use as a winter car this year and I have a quick question or two. The car never ran "right" when they owned it but good enough to get around safely and reliably. When I bought it I decided to give it a full tune up, new plugs,wires,pvc valve, clean the TB and Maf and new air filter along with an oil change. After all that the car has ran considerably worse under load at idle or driving, theres an obvious miss somewhere no check engine light at all. Over the past few weeks ive double,triple, quadruple checked everything and it all checks out I even put 3 new coil packs (delco) on it to no avail. I also checked voltage and resistence on all the major sensors. Still runs bad under load with a miss but runs pretty good overall in park or neutral.


Anyway yesterday I decided to check out the ICM and make sure that was good. I unbolted it and made sure all the grounds were good( I couldnt find any "grounds", are they the bolts that hold it in?). Everything looked ok and I cleaned up any dust/corrosion in the area. After bolting it back in and wiring it back up the car ran worse! Barely stays running and now dies when you put it in gear. So I've concluded that the ICM in the car is done for. Theres a junk yark around here that has an 86 PA with the ICM still in it that id like to go get but Id hate to gamble on another 25+ year old part. Are the ICMs from other buick/pontiac newer cars compatible? Id be willing to do a few minor modifications to make it work if needed. Any help would be greatly appreciated and if you have a suggestion please let me know. Thank You!

Well, the first thing I would do is a coil output check with an ST-125....

This engine had 3 separate coils? Thought that year had the single Magnavox coil.....

Also, the MAF'* were known to fail....quick test was to hit it lightly with the handle of a screwdriver, and if the engine stumbled, that was your problem....

Ok Ill look into that spark tester. Anything specific I should look for when testing? Basically just see if its firing or not?

I think its hit or miss when it comes to the Magnavox coils coming in these cars, Ive seen some that have them and some that dont. Maybe mine come with it originally and swapped in a Delco style? The ICM seemed kinda rigged into place when I was taking it out, there are six studs that the module slides onto and only 3 of them were still attached to the bracket with the other 3 not attached and freely moving. My first though was maybe those help with grounding and my problem could lie there?

And I did the maf test aswell already( was maybe the first thing I tried) hit it in multiple places with no change. I did unplug it prior to the car running terrible and it stumbled and died when I put it into gear.

i believe the coils ground through the bolts to the bracket, also think if you see one with a delco it has been replaced.

Ok I figured they grounded via the bolts. Perhaps my problem might have something to do with that since like I said before those bolts aren't the greatest in the world.

i have never worked on a car like yours, but the newer ones with the delco icm/3 coils, they ground to the bracket and there is a ground wire attached to the bracket, maybe you will have to add this. and clean the bolts and bracket so they make good contact.

I saw no wire when I was checking it out a couple days ago so I'll make sure to add one. Do you know the spot that the wire is attached to? Or should I be fine with just attaching it to one of the grounding bolts then to the chassis?

on mine there are big bolts attached to the side i think and the wire has a big terminal has a big hole, which is not really handy if you just adding it. you could just take a standard blue terminal and some 12-14g stranded and attach it to the bracket where ever there is a spot if its easier and to the chassis. just make sure everything is clean and bare metal and paint it after for corrosion protection.

So today I cleaned up all the bolts, grounding points, etc. Only to find out that the battery is dead now because of sitting! Just my luck! Anyway I never got a chance to start it but I just want to possibly confirm with somebody that my ICM setup was done properly by the previous owner because it just doesn't seem right.

There'* six long bolts that go through the ICM and the coils and get nuts put on them to hold the whole thing together. My question is shouldnt all six of them be attached to the ICM bracket? Because only three of them are on mine. If you are looking at the bracket from the pass side the bolts that are attached are the top left corner, middle right, and bottom left corner. Seems like that might mess up grounding? I can take pictures if needed.

Also one last question. My ICM doesn't have a pin on the left plug on the left side yet the wiring harness has a wire for it.

Thanks for the help so far guys. It'* very hard to find any info on these cars/engines and with this being my winter car every little thing counts to get this car running.

Heres a stock picture of the icm in my car. Exactly the same except for the pin on the very left thats missing on mine.