Hi, iīve trying ty help my friend with his -86 Firebird that hasnīt been running for ages, well over 5 years. Fuel pump was original cause why stopped running, but now when he finally get it replaced. Thereīs a new symptom.

Car idles quite decently, and if you apply gas very lightly, saying tps under 5% it raises rpm, but pressing bit more it completely chokes and stalls.

It gives code 34 (too low maff signal? right?), and when measured from ecu B12 pin, it gives 0.7V when idling 900rpm, when giving rpm, it raises about 2.5v when 4000rpm.

MAF power relay connector is gone, and connectors was wrong way around in relay. I did go though wiring diagram and put those in place correctly and glued in place, but may have done something also...?

Part numbers are 14078907 in both, maf power and burnof relays and 10094701 in fuel pump relay.

Any ideas what to look? I couldnīt yet find whole wiring diagram, just for maff wiring. Think that next thing is to check that tps signal is correct in ecu connector (just need to find what pin is that, measured from tps it is 0,55v when tps 0% and raises like it should.








...sorry for languege mistakes, iīm from Finland.

 

sorry, douple post.

 

I'm not thinking as technical just yet. What is the fuel pressure now? IF it's too low you may have a similar symptom. Past that, it sounds like you may have some wiring to dig through, and or, a bad MAF.