I have a 91 Firebird 305 TPI, with Dynamic EFI's EBL P4 ECM.
When I first got it and pluged it in and started the car, I noticed immedieattly that it had a slightly high rev (cuz of starting) but that within a second or 2, it would really drop down the RPM's quite low (much faster than stock ECM) and there wasn't really much of a problem, because I lived in FL at the time...

Now I live in a much colder climate... So it wants to behave the same way, but since the engine is so cold, when it slows down, it's rough, RPM speeding up / slowing down... the warmer it gets the better that smooths out... and when fully warm, idles perfectly.... I have replaced all the sensors (not recently though).

Is there an adjustment I can tune for to just keep the RPM's higher for longer instead ?

Or is there something else I'm missing ?

Thanks!

Raf

 

Completely unelated but now that I have seen it I can't unsee it.

On the left in your mini bio in the Engine section you have R69. It should be R6P for the Performance Enhancement Group.

 

My wife won't let me change it 😔