Got rid of the modified prom that was supplied by TPIParts.net in favor of my stock APYN bin.

Now I have a cold start idling problem. With the old TPIParts Prom, truck would start dead cold (34f) and high idle normally, gradually reduce but never stall. Now that I am running the stock APYN bin albeit modified (vats disable, manual transmission flag select, air disable, fans on at 200 of at 186) it will not idle when cold. Starts, revs build, then fall, engine stumbles (I can hear the air filter get louder as the IAC opens) and then it stalls. Restart, same thing. If I hold the R's up for about 30sec it will idle on its own.

Now on to the problem, due to the proximity of the O2 sensor to the engine it warms up really fast and starts giving me info via my Autometer O2 gauge before the ECM enters closed loop. It is telling me that during warm up it is running very lean, if I blip the throttle it runs through stoich to the bottom end of rich and then falls to lean again.

What is the best route to take to enrichen my idle mixture?

 

You need to keep the choke "on" a tad longer. Not to much. And the coolant modifier for OL you need to enrichen for those temps say under 140dF. Not to much. Dont think you want to enrichen the OL tables but you could a small amount. I run OL table at 14.3/1. I run stoich constant at 14.3 for E10. I have my CL lean median rich skewed about 10% richer on mV. No emishions stuff on my car.

 

What are the "OL" tables......? Sorry new to this.......

 

Each mask is a bit different. I dont have my laptop here at work but I think it begins OL-RPM vs MAP. It is a table of A/F for each cell like 200 rpms at 40 MAP might be 14.7/1 for a value.

Are you MAP-Speed Density or MAF? If MAF I am uncertain what it may be called. Check the stickies for specifics for your ECU/Definition file.

You can search TunerPro. Search for "OL" and see what appears? I suspect there are several constants/tables that deal with OL.

 

I am MAF, I found "Open Loop AFR Ratio % Change vs. Coolant Temp", does that sound like what I should be looking for?

 

Yes, open loop change to AF ratio % vs coolant, increase the change to AFR % values in the lower temps to get a fatter mixture.

May want to tweak the startup enrich decay delay vs coolant also.

 

I am imagining that changing that will keep the "richness" on longer as the engine warms up?

I am also right in the middle of a Compare Bin in TP5.0 to see what differences there are between the stock bin and the bin supplied by TPIParts. So far most tables match, but the MAF Tables are slighty different.

 

startup enrichment just after the engine fires up, might help keep it from stalling out

warm up is done w/ the afr change vs coolant temp

 

Awesome, will start goofing and testing. BTW is there anyway to change the Celcius to Farenheight?