He still can use the ROM changing which sensor the car uses

 

Opening post updated. Issue still there with cold temperature outside, I ordered GM MAT and bung, I'll retune to see how things goes.

If it doesn't work, I'm surely going back to closed loop idle and cruise to get fuel trims corrections. I really understand why they are in the ECU

 

im having the same issue with my car. after about 10 minutes of driving around it will go rich and go back to normal after a WOT pull. I'll keep following your updates and see what fixes it.

 

I might have no answer because I switched back to closed loop which compensates all these variations. It's most likely fuel temp related. MAT on the UICP would have solved it I'm pretty sure.

 

ok well ill have to wait till i get back home. when i was still on the MAF sensor i was getting a code for fuel temp sensor. maybe that might be my issue. ill swap out canniesters/sensor when i get back home.

 

Does anyone have any further insight into this? A friends car that I tuned is having the same issue. It never seems to do it when I datalog the car so I can't really determine what is causing it. I was thinking it was an issue with the air temperature sensor, however if I plug out the sensor entirely the logged reading goes to 75F (from anywhere between 95F and 105F) and there is no significant change in AFR. This suggests to me that the temp compensation has no significant effect on the AFR. The car is using a GM sensor in the UICP.

 

Ok, it's been a long time and I don't have the car anymore.. but if I remember correctly, it was my wideband 02 sensor going nuts. Changed it.

But, I changed my fuel pump in the same year, so i'm not sure exactly which fix lifted the curse.

 

Ok, thanks for the update.