88 LE 112k - runs rough on freeway-FIXED!!!

Parley with regards to your 1987 to 1991 Bonneville, Olds 88, Olds 98 86-90 or Buick Le Sabre, Le Sabre T-Type and Park Avenue 85-90 . Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.
Drive-In
SLE Member
SLE Member
Posts: 51
Joined: Sun Jun 01, 2008 2:29 pm
Year and Trim: '88 LE - no mods - 112k
Location: L.A. North-Western Hemisphere

Re: 88 LE 112k - runs rough on freeway

Post 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?

Image



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
"Like a rubber-necked giraffe, y'look into my past, but maybe you're just too blind t'... see" - Leon Russell
Zeik75
Posts like an L36
Posts like an L36
Posts: 999
Joined: Wed May 02, 2012 3:29 pm
Year and Trim: 1988 LE
2000 SSEi
Location: Lincoln, NE

Re: 88 LE 112k - runs rough on freeway

Post by Zeik75 »

Like so

bottom is the plug for the ICM.
Image
right is plug for ICM
Image

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.
Image
-Austin-
1988 LE, Intercooled L67 loading......

2000 SSEi R.I.P. Dead now :( INTENSE FWI, polished LIM, P&P supercharger, custom radiator, standalone trans cooler, trans-go shift kit (donating to the 88)

2002 2500HD Silverado with the 8.1 Vortec and Alison tranny. Likes to eat GT Mustangs and lots of tires, and all while stock!

yourgrandma wrote:And thats how I got my mom pregnant.
Drive-In
SLE Member
SLE Member
Posts: 51
Joined: Sun Jun 01, 2008 2:29 pm
Year and Trim: '88 LE - no mods - 112k
Location: L.A. North-Western Hemisphere

Re: 88 LE 112k - runs rough on freeway

Post 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... :dontknow: :)

But that doesn't stop me. :bwoohoo:

will this thing blow up?
"Like a rubber-necked giraffe, y'look into my past, but maybe you're just too blind t'... see" - Leon Russell
Zeik75
Posts like an L36
Posts like an L36
Posts: 999
Joined: Wed May 02, 2012 3:29 pm
Year and Trim: 1988 LE
2000 SSEi
Location: Lincoln, NE

Re: 88 LE 112k - runs rough on freeway

Post 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.
Image
-Austin-
1988 LE, Intercooled L67 loading......

2000 SSEi R.I.P. Dead now :( INTENSE FWI, polished LIM, P&P supercharger, custom radiator, standalone trans cooler, trans-go shift kit (donating to the 88)

2002 2500HD Silverado with the 8.1 Vortec and Alison tranny. Likes to eat GT Mustangs and lots of tires, and all while stock!

yourgrandma wrote:And thats how I got my mom pregnant.
Zeik75
Posts like an L36
Posts like an L36
Posts: 999
Joined: Wed May 02, 2012 3:29 pm
Year and Trim: 1988 LE
2000 SSEi
Location: Lincoln, NE

Re: 88 LE 112k - runs rough on freeway

Post 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.
Image
-Austin-
1988 LE, Intercooled L67 loading......

2000 SSEi R.I.P. Dead now :( INTENSE FWI, polished LIM, P&P supercharger, custom radiator, standalone trans cooler, trans-go shift kit (donating to the 88)

2002 2500HD Silverado with the 8.1 Vortec and Alison tranny. Likes to eat GT Mustangs and lots of tires, and all while stock!

yourgrandma wrote:And thats how I got my mom pregnant.
Drive-In
SLE Member
SLE Member
Posts: 51
Joined: Sun Jun 01, 2008 2:29 pm
Year and Trim: '88 LE - no mods - 112k
Location: L.A. North-Western Hemisphere

Re: 88 LE 112k - runs rough on freeway

Post 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.
"Like a rubber-necked giraffe, y'look into my past, but maybe you're just too blind t'... see" - Leon Russell
grant111
SE Member
SE Member
Posts: 11
Joined: Sat Oct 12, 2013 9:01 pm
Year and Trim: 1990 Oldsmobile Eighty-Eight Royale

Re: 88 LE 112k - runs rough on freeway

Post by grant111 »

I have JB welded a magnet into place. It worked fine. Directions here: http://padgett.performanceresearch.us/cars/cammag.htm
Drive-In
SLE Member
SLE Member
Posts: 51
Joined: Sun Jun 01, 2008 2:29 pm
Year and Trim: '88 LE - no mods - 112k
Location: L.A. North-Western Hemisphere

Re: 88 LE 112k - runs rough on freeway

Post 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
"Like a rubber-necked giraffe, y'look into my past, but maybe you're just too blind t'... see" - Leon Russell
Drive-In
SLE Member
SLE Member
Posts: 51
Joined: Sun Jun 01, 2008 2:29 pm
Year and Trim: '88 LE - no mods - 112k
Location: L.A. North-Western Hemisphere

Re: 88 LE 112k - runs rough on freeway-FIXED!!!

Post 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.
"Like a rubber-necked giraffe, y'look into my past, but maybe you're just too blind t'... see" - Leon Russell
Post Reply