I have been driving around for about 2 weeks with my new PFC. Some times when I start the car it starts to rev to 2000rpm then goes to 1000rpm then back to 2000. This happens for about 2 minutes then it revs to normal again.

This has happened about four times so far. Yesterday I pulled out from a petrol station with this happened and I got wild stares from everybody especially when I pulled up at the lights. They must of thought I was a crazy street racer !!

Whats the story on this ?

 

The PFC takes a little while to learn the idle. The problem may clear up on it's own.

Other possible problems...

vacuum leak(s)
throttle body air bleed screws need adjustment
ISC is bad or needs cleaning
thermowax warmup is out of adjustment
TPS is out of adjustment
PFC fuel maps need adjustment

Try doing a search for idle problems or idle hunting.

 

This happens about 99% of the time with a new PFC install.
Doing a serach on IDLE will give you many hits going back to 2001.
If you really know you car, you can play around with the throttle idle screw or air bleed screw.

 

But most of the time I have no problems. Its starts fine idles at 1500 when cold the settles to normal 800 Ok. Its when you stop somewhere for a little while then start up to drive off and toget this bouncing up and down from 1000 to 2000 like your going to the drags. It soon settles down to 800 again its just anoying. I have not tried switching off then on again just to see what happens..

 

I had similar problems with a modded engine with a stock ecu.

Why do you think it is HUNTING for an idle settings? Do you know anything about feedback control systems?

Anyway, do as I said earlier and HELP the PFC by manually adjusting the idle higher or lower by adjusting the air flow through the throttle body.

Have you done your search yet?

 

Ok Ok I'll check it out ! Yep I've done a search. Heaps of hits I'll go through them to find out more. THanks