this may sound like a stupid question, but i need to know. what table to i adjust to change my AFR at idle? i know how to do WOT tuning, but what should i do for regular tuning?

 

That depends on if you are running open loop only, because in closed loop the PCM will constantly adjust for 14.7:1 AFR. Lots of people run PE idle by setting the throttle percentage for PE to 0% at 800 & 1200 RPM then you can adjust by the PE vs. RPM table.

 

Hey Grover

Do people do this to save on gas?

What is the reason for doing it. sounds interesting, but why do it?

Ben

 

I believe it is done mostly to counter the effects of a large cam and reversion in the intake that sends your blm's wacky at idle.

As far as a/f ratio at idle...stuff like that should be taken care of by the mass air flow sensor and O2. What problems are you having that you think this is affecting?

 

Dan was pretty much right on most of the reasons. But I did it because my car was so rich at idle it would hurt your eyes. I had to crank up my fuel pressure so high that I wasn't going lean at WOT and in turn it made the car rich at idle.

 

Chad-
Isn't that an indication of inadequate programming or undersized injectors?
Seems to me that bumping up fuel pressure in order to tune WOT is a band-aid fix....that's all.
Anyways, how did the PE idle work for you?
I tried it on a buddies 93 and couldn't get it to work. Apparrently the 93 computers are different as far as getting the car to idle in PE mode....I still haven't figured it out.

 

Dan you are correct. At the time I couldn't afford larger injectors so I just turned up my fuel pressure so I wasn't >100% duty cycle on the factory injectors. I have some 39# injectors that are going in over the winter and will be doing lots of tuning next spring. I will be going back to closed loop idle to see if I have the BLM split that is caused by large cams at idle.