Alright, I installed the PFC+commander today and it was doing a rough idle when I first started up. I did a search and saw that it was part of the install process and that the PFC does this for initializing. After waiting about 10 minutes or so, the RPMS dropped to around 1000-1200 and would jump back and forth and I decided to go on a drive testing it out. Car ran great and everything but when I'd come to a stop light or anything like that, the idle would still jump up and down from 800-1200.

After about 20 minutes of driving I came back home and it was still doing it whenever I wasn't on the gas and was wondering if I messed up the learning when I started the car and then turned it off before it learned everything or will this disappear over time?

 

Idle screw typically needs adjustment too and the learning process takes about 30 minutes:

http://www.clubrx.org/media/pfc/PowerFC_FAQ.pdf

 

Where is the idle screw located? The pfc was already tuned but for a street ported engine and other mods so I had to reset it

 

towards the bottom of the throttle body, under the compression tube, when you take off the elbow, there are 4 screws, remove the bottom 2 and move the hose out of the way and you should see it.

 

The document I linked to describes its location in detail.

 

Make sure that your O2 sensor is turned off on the PFC.

 

You don't need to turn off the O2 sensor to learn idle. It should be done on a RECALC but since he has reset his PFC it should not be an issue yet.

 

i thought the idle adjustment was on top of the throttle body...that large flathead screw....ive messed with it and brought the idle down

 

that's for the secondary throttle..

 

I didn't say that he needed it turned off to learn idle. I said he needed it off period.

Mine did the same thing as his. Surged up and down, up down, drove me nuts for about a week. My tuner/mechanic called me up and said "I think I forgot to turn off the O2 and that why you are getting that irratic idle. Go try it". I went outside and turned it off. LIKE MAGIC steady and controlled idle. My understanding is that with the O2 sensor on, the PFC is on a constant loop trying to correct itself but it never does. Hence the erractic idle.

 

how do you turn off the idle on the PFC?