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Re: 88 LE 112k - runs rough on freeway
Posted: Thu Sep 26, 2013 1:33 am
by Drive-In
Zeik, what a brilliant post! Thank you.
Sorry to delay getting back - got sidetracked. Here's what I've got up to now:
After resetting last week, I checked again today and even without the check engine light coming on at any time, it set a code 42.
For the sake of simplicity and because from everything I could tell, it seemed like the thing to do, I bought a new AC Delco ICM from ebay for $ 100.00. They are $ 200 - $ 300 everywhere else I looked.
The ebay seller has a 100% rating and has a ton of parts for vintage cars. He said he got the Control Module from a now-closed dealership - that's why he's considering it as new. I hope I dun ok.
I'm gonna try to get the picture up. Can you help me with this one part?
How am I going to know which blue wire goes to which coil connector once I've got the coils off?
Help me Mr. Wizaaaard...
Thanks again for a
great post. I think in pictures and they're in focus and on topic. I have a Cam Sensor on the way so I'll look in the hole for the magnet when I replace the sensor. I really do hope this new ICM solves the problem though.
Mike
Re: 88 LE 112k - runs rough on freeway
Posted: Fri Sep 27, 2013 7:01 pm
by Zeik75
Like so
bottom is the plug for the ICM.

right is plug for ICM
The coils go odd #'s to left and even #'s to the right.
Also not to be a downer but how you drive greatly affects how long this ICM will hold up. highway cruising and low engine rpms keep it cooler so it lasts longer, but if your are like I was with the regular 6 grand WOT runs It will kick the bucket before long. All 4 of my ICM failures were because of either shorts within the ICM itself or the goo stuff melting and causing a short.
That said I feel you are better off with the AC Delco one than aftermarket, but the overall design of that part simply isn't very good. notice the tiny cooling fins on one end, otherwise it is all flat. That allows for overheating when lots of current is moving through it (high RPMs). Good luck with the part just keep this in mind.
Re: 88 LE 112k - runs rough on freeway
Posted: Fri Sep 27, 2013 10:25 pm
by Drive-In
Zeik, thanks for the photos... worth, uh... 2,000+ words... jk

The pictures actually help
alot.
Correct me if I'm wrong...
The
blue wires are all on ONE circuit. How can it matter which order they're in as long as they provide (either) waste spark or main spark (probably have that idea worded wrong).
What I mean to say is: 3 connectors are receiving power from 1 feed wire. They're not being fed independently so firing order isn't an issue - only power to the coil itself.
I don't even understand what I don't understand...
But that doesn't stop me.
will this thing blow up?
Re: 88 LE 112k - runs rough on freeway
Posted: Sat Sep 28, 2013 1:15 am
by Zeik75
As far as i can tell yes. It seems silly but i guess it works out in the end. The reason it is wired that way thouh is so that the wires will lay in there properly. The order shouldn't matter for functionality really. Also another reason this is just a bad design IMO.
Re: 88 LE 112k - runs rough on freeway
Posted: Sat Sep 28, 2013 1:19 am
by Zeik75
If for some reason it does matter though the worst that will happen is it won't run or it will run like crap.
Re: 88 LE 112k - runs rough on freeway
Posted: Fri Oct 11, 2013 6:50 pm
by Drive-In
Update:
Installed the new aftermarket Magnavox-style ECM. Runs even better but after a road test, it still has the under load misfire.
Without having removed the Camshaft sensor, rotated the crank and looked at the magnet, I'm thinking the magnet is still there but possibly mostly shredded. Enough there to get a signal to the ECM but weak or intermittent. Replacing the ECM cleared the code 42. No codes are set now.
Anyone have experience on how to glue a new magnet onto the cam sprocket instead of pulling off the whole front of the engine to get to it?
Thanks for reading
Mike
ps Hey Zeik, you snowed in up there yet? Go easy til you get your ice legs.
Re: 88 LE 112k - runs rough on freeway
Posted: Mon Oct 28, 2013 9:22 am
by grant111
I have JB welded a magnet into place. It worked fine. Directions here:
http://padgett.performanceresearch.us/cars/cammag.htm
Re: 88 LE 112k - runs rough on freeway
Posted: Mon Oct 28, 2013 1:03 pm
by Drive-In
Hey Grant

Thanks for that. I took a look and the magnet was fine. I started a new updated post on this thinking it would be simpler. The fact is I had a transmission failure last week and I think that's the problem. Something in the valve body. I'm looking into rebuilding that at the moment, so I hope that's the solution. Thanks for your help.
Mike
Re: 88 LE 112k - runs rough on freeway-FIXED!!!
Posted: Mon Apr 14, 2014 1:39 pm
by Drive-In
In case the edit doesn't bump it to the top.
Replaced the driver's axle and it fixed everything. Huge thanks to an incredible group of people on the forum. THANK YOU!
Fixes include: Plugs, Wires, ECM, Coil Pack, Upgraded Vacuum Modulator, O2 sensor and driver's axle. Like a rebuilt car! Thanks again, everyone.