I had a similar issue with my 91 L98 Corvette which used the same ECM along with about 10 other GM carlines.
It would set three or four random codes ... The used junkyard ECM i replaced it with was an AC Delco rebuilt which
gave me the tip-off that there was a batch failure of that bundle of electronics. Kinda like our Bose speaker amplifiers ...
Anyway, if nothing else shows up, Marc might want to swap ECMs with a known good one (hello Gary James?).
On May 1, 2018, at 9:39 PM, JOHN wrote:
> Donít know if this helps but bought a 91 Buick Regal GS new for a daily driver. Great car for about 4 yrs. One day on the interstate car started misfiring, bucking, loss of power. Pulled off and everything looked normal under the hood. Refired normally and ran good rest of way home. NO check engine light. Made appt with buick; no codes and they found nothing abnormal. Ok for several months then did it again. On interstate, all temps normal but at running temp. Rescanned, no codes. Suggestions of cam sensor, wires, plugs, and especially coils. Replaced coils and wires. Couple of months no problem then again. Replaced fuel filter. This went on for quite some time. Eventually got hooked up with an independent ex GM tech I trusted. We switched cars for the weekend and he drove the GS around with a Tech 1 hooked up. Saturday night it acted up. He looked down at the screen on the Tech 1 and it was blank. No data. Replaced ECM and problem went away permanently. Was told early to mid 90s GM cars were prone to ECM problems. Something to look into.
> TOPICS: TECH or SALOON
> Problems? Contact ZR1Mom at: [log in to unmask]
> ZR-1 Store @ http://www.zr1net.net
> ZR-1 Saloon Keeper
TOPICS: TECH or SALOON
Problems? Contact ZR1Mom at: [log in to unmask]
ZR-1 Store @ http://www.zr1net.net
ZR-1 Saloon Keeper