GM tech needs help, '88 Park Avenue VIN C

[journeyforce]

I am very glad it worked out for you? The 1980's FWD Park Ave was a comfy car to drive and those lights on the outside of the B pillar with their soft white glow looked sharp. My grandfather had a 1986 PA

Did you just swap out the ECM totally or did you put the PROM chip from your car into the donor ECM first? I wonder if it was a bum PROM chip?

Well anyway I am glad it worked out for you

 

[Fred482]

I swapped the PROM from my vehicle to the donor ECM. Just a habit from the dealership days. I did notice the PROM from the donor car had the same ID number(s) and probably would have worked fine. Not knowing how much, if any, data was still present in mine, I decided to use it and, if it didn't seem right, I could swap it later. Everything worked and the scan tool readings were right in the middle of the range. Block learn and Integrator readings were identical to what I had recorded from past road tests, when things were running smooth. I have several road test files on record, they come in handy for comparison.

I drove it to Salem, city traffic, several stops, several road construction delays, etc., yesterday without a misfire. Temps in the 70's ambient, warm enough to use A/C to cool it after sitting in parking lots, no problems, all went well, trip was over 60 miles.

The real test began a few hours ago....the wife switched her stuff from the '94 to the '88 and left for work, 14 miles away. No phone calls, all is good......I'm always glad to see her when she returns but it will put me more 'at ease' when she gets home safe tonight...;-)

 

[Fred482]

Hi Fred,
Thanks for clarifying that the fix was the ECM.

I can recall back in the mid to late 90s having ECMs throw us for a loop with regards to proper diagnosis of a variety of driveability problems. In the same time period Standard Ignition had a batch of bad, rebuilt ECMs that would complicate diagnosis even further. It got to the point that for awhile we just called the salvage yards for ECMs so we'd be sure of getting a good one.

You did the right thing changing out the ICM/coil pack. Those Magnavox ICMs were troublesome. Replacement ICMs had to be a money maker for the aftermarket for a few years.

Keith

Hi Keith,

Interesting that you said this, one of my local techs, a guy I've known for 40 years, said the very same thing. He now owns the indy shop that his dad started many years ago, he's seen a lot too. He runs a towing service, that I use as a Fire Chief. He suggested the ECM when I called last week, seeking a second opinion. He said, " Replace the ECM, if that doesn't fix it, bring it in and we'll hook it up to the scope...."

Thanks again, your insight is greatly appreciated....🙂

Fred