Okay, I have a 88 model GTA (cold start setup), and have converted to the 1989 ARAP file. The engine is a 355 with a pretty agressive cam. Here's what I've done so far. I've made my own AFPR for adjusting fuel later, wired my passenger fan to the drivers fan, so the ECM can control both fans at the same time. I have a 160* stat, and tuned my ECM to turn the fans on at 185* and off at 175*, and changed my base timing to 8*.

I've disabled the cold start injector by unplugging it and removing the fuel line to it. Everything else is connected (even the cold start sensor...maybe I need to unplug that too...not sure, but if anyone knows how that cold start crap works, let me know).

Now, when I start the engine, it won't idle right. It seems like it's missing terribly. I have to keep the foot on the pedal just to keep it running. I've adjusted the TPS and IAC per the "howto" on this board, and when the car goes into closed loop, it idles GREAT!. Even the BLM is right around 130 (still have some adjusting to do).
Just wondering if there's any tuning parameters I need to change on my ARAP to get it to idle and stay running better when it's cold. Any suggestions?

 

If it seems to be running fine in Open loop you could play with the Open Loop AFR % Change vs. Coolant Temp table and see what it'll do for you. I had these issues once (but I don't have the cold start stuff on my 89) and raising the table values to 13.67 at the 90, 111, and 133*F seemed to clear it all up. I also lowered the Coolant Temp Spark correction disable temp so I would rely on the main spark table instead of the lackluster cold coolant spark table.

HTH,

Brian P

 

Okay, I'll try that. I'm using the advance timing of the arap, because I'm using higher flowing aluminum heads.