Buick 3.8 Ignition module/coils removal

[Touring5]

A couple of days ago my '87 Century with 3.8L V6 began running horribly. I checked and was getting no spark on two cylinders (fed by one of the three coils on the ICM/coil pack). I have removed the 3-coil pack (single part) by removing 6 torx screws, but the module that it connects to and mounts on top of is still there. I'm not sure how to remove the module. It has an elaborate bracket that is screwed to the engine in ridiculously hard to access points. I'm hoping that the whole bracket doesn't have to be removed. While it's an old Buick, it only has about 59K miles (was elderly mother's car) - in it's life the coils or ICM have been replaced 3 times already.

Anyone who can shed some light on how this module is mounted could really help me a lot. Also, were the coil unit and module sold as one piece or with different P/N's. There are no P/N's on the coil unit and without removing it, I haven't seen the P/N for the module. If anyone knows of a good website that shows diagrams and P/N listings that would be huge.

In short, any and all information would be swell!

 

[OceanDoctor]

GM really dropped the ball on coil pack quality/design. I've dealt with this problem repeatedly and after enough times, the vehicle just got scrapped. That was when this "base" thing [censored] out, couldn't be bothered to pay to replace it or do the labour involved. To you, I wish the best of luck!

 

[Touring5]

Originally Posted By: OceanDoctor
GM really dropped the ball on coil pack quality/design. I've dealt with this problem repeatedly and after enough times, the vehicle just got scrapped. That was when this "base" thing [censored] out, couldn't be bothered to pay to replace it or do the labour involved. To you, I wish the best of luck!


I feel your pain. As mentioned, this car has had ignition module/coil problems dating back to the first year after it was purchased (new). I happened to be doing contractor work onsite at a Delco Remy plant where many of the ignition products were made - including the Quad 4 system. They seemed to have really top notch manufacturing techniques such as robots and vision systems (this was in '87 and '88 mind you), but the designs and components were an entirely different matter.

But, yes, this was certainly one component that they could never get right. BTW, this car also had the famous "morning sickness" power steering issue. How that wasn't part of a safety recall, I don't know - but I always feared my mother would get hurt when the steering refused to work. To my amazement, I "cured" the problem a couple of years ago with Lucas power steering treatment...

 

[OceanDoctor]

Hey I wonder if there is any way to retrofit aftermarket coils in place? Maybe some MSD Blaster e-core coils. Perhaps there exist some direct drop ins eh

 

[1 SX]

Hi this is from the 82-96 GM Haynes Repair Manual..

.. Yes you do need to remove the bracket...

- Label all remove all spark plug wires.

- Unbolt the electrical connector at the module

- If equipped, detach the vacuum lines and the electrical connector from the EGR valve solenoid on the left end of the coil/module assembly.

- Unbolt and remove the DIS or C3I and support bracket assembly.

- Using a Torx screwdriver remove the coil-to-module attaching screws.

- Separate the coil and module assemblies.

- Open the coil and module halves, Label, then detach the wires between the module and the coil assemblies from the spade terminals on the underside of the coils.

- Unbolt the module from the support bracket.

- Installation is the reverse of removal. Be sure to attach the wires of the new module to the coil assembly spade terminals in exactly the same order in which they were removed.

Here is a new drop in ignition coil pack.
Part No. E45Z BWD
Part No. GN10139 Delphi

 

[Touring5]

Thanks for the info. Evidently there are fasteners under the module that attach to the bracket. (Not looking forward to removing that bracket - gonna be a lot of cussing and scraped skin...).

 

[1 SX]

You would be correct. 3 8-10MM nuts...2 at the bottom one on each side of the ICM connector, then 1 up in the upper middle..

Best of luck!.

 

[Touring5]

Well, since I already have the coils off, I am going to see if I can find a way to test them. If not, I may still just try to get the replacement coils and see if that fixes the problem so I don't have to remove that silly bracket and it's stupid mounting scheme.

 

[sciphi]

http://www.pontiacbonnevilleclub.com/forum/viewtopic.php?f=44&t=1684

Just convert it to the newer 1993-1995 style ignition system with 3 separate coils. It's much more reliable, and troubleshooting it is easier.

 

[Touring5]

Well, I think I've been able to determine that the coils are actually good.

After a bit of searching, I found this video:

GM Type I Ignition System Troubleshooting...

All three coils had identical secondary resistance. Since the video indicates that the coil pack can be installed essentially backward, as long as the wires are in the correct order it works the same. Doing so resulted in the same two cylinders not firing, even though at that point they were connected to a different coil (I couldn't have done this if the suspect coil was the middle one).

Looks like a aftermarket ICM can be had for less than $120 and I can use the existing coil group module. That bracket scheme is going to be a pain - typical GM, you have to practically remove everything under the hood to accomplish a fairly simple task....

As to replacing the whole thing, I might consider it if it weren't a 24 year-old "beater" (albeit a nice beater )