Hi

My 89 g20 was running very rich and i have got it to run better. It is a 305 that had 350 injectors and 350 fuel pressure regulator. All replaced now :)

However it still doesnt idle good at all, still running too rich.

I know the IAC works as i have tested using paperclip in aldl mode, and it can fully extend and retract, but it doesnt seem to want to retract in idle-


So my question is how does the ECM control idle with the IAC? Since the engine doesnt know if its running rich or lean on startup (O2 not up to temperature) i guess it resorts to the BLM tables?

So, is there a factory blm setting hard coded in the ECM that car resorts to and then improves upon? Or is the BLM always learned by driving the car? If so, does it "reset" if i unplug the battery for long periods of time?

Could i get the IAC to open up on idle by slowly lowering rpm and giving the ECU time to learn and adjust blm tables accordingly?

Thankfull for any answers :)

/Alex