as some of you know i was having a mass air flow issue which was making my car run pig rich.....so i replaced the MAF this morning and the car seemed to run great....i let her run for about 30 minutes in my driveway and then left for my 45 minute drive to work....about halfway the check engine light came back on but the car was still running great. i figured its gotta be something else. so when i got to work i plugged in the diagnostic and ran the codes and there was NO codes but the light was on. so then i went into datastream....the VSS was going crazy...it said like 90, 134,0,10,80 etc. etc and y prom ID which is normally 8291 i believe..........started at 0 and counted up to 200 and then back to 0....so i reset the computer again and it seemed to be running great again. so do you guys think its time for a new ECM?


its an 86 t/a with a 305 tpi

 

Maybe it's time for a new vehicle speed sensor. The only time i've ever seen a computer go bad, it showed multiple values going wacky.

You could have a bad ground wire on the ecm as well.

 

ok, to elaborate a little bit here on my problem, have an SES light, no code, comes on after 15 minutes of driving, car running perfect. put it on datastream and every value is at 0, except VSS which bounces around up to 134. Prom ID constantly changes. this is all with the car running at operating temp:


RPM: 0
VSS: 0, 25, 85, 134, 0 etc, etc
MAF: 0 g/s
O2 : 0.00 volts
TPS: 0.00 volts
MAT: -40
Coolant temp: 25
Inj. Pulse: 0.0

 

THAT looks more like an ECM problem.
Do you have a spare memcal laying around that you could try?

 

wouldn't you know it i do have the stock one lying around, the only thing about that one is it goes back to the old operating temp....the ole fans come on at 230.....too hot for me, but i'll swap it out and see what happens if i get a day where it isn't raining. what i don't understand is how the car is running awesome