I am running the pfc with stock base map. my car has all bolt-on mods and I am running a bonez hf cat with a trust exhaust. my fuel system is stock and so are my injectors and ports. so my problem is the car runs different from day to day as far as idle and drive ability. yesterday while driving the car I had Idle issues while coming to a stop and while decelerating on Cruz. the idle would bounce up and down a little before settling. today I drove the car without changing anything in the settings or with the idle control on the throttle body. the car ran great without the idle problems or deceleration after Cruz issues. so is this just a characteristic of the pfc to react differently from day to day or will I need to take the car for a long cruz say 50-60 miles to resolve the issues. since I installed the pfc I've driven approximately 100 miles while experiencing these drive ability problems. dose it take more driving to get the pfc to settle down and learn I would think a 100 miles would have taken care of this learning thing.

Jeff

 

All has to do with the Idle Control System (ICS). Sometimes you have to help the PFC learn idlel correctly by adjusting the Air Adjusting Screw (AAS) in or out by 1/4 turn until the sweet spot is found. Also check the TPS voltage with the commander when the engine is fully hot.

Many threads have been posted here about these since 1999.

 

I've adjusted the (AAS) and the problem went away for a day and came back. I've checked the TPS on the commander when hot and its within range per the manual. today the car ran flawlessly plenty of power, good vac psi, and no problem at all with idle and decell Cruz. I am hoping when I get it dyno tuned with a wide band sensor these problems will get worked out and the car will run the same every time. the only thing that I did different today was use the heater since it was cold outside but I don't think would do anything with the Idle.

Jeff

 

In my experience, after you have adjusted the AAS it helps to reset the Power FC and perform the idle learn procedure in the manual. Reset the PFC, turn off O2 feedback if you have no cat/airpump, and perform the idle learning procedure. The idle will continue to improve a little as you drive it.

The rest of the idle problems are usually fixable by wideband tuning of all the various tables in the PFC (including air temp correction). The idle will surge on hot starts if the mixture is too lean.

 

after adjusting the (AAS) I reset the pfc and did the idle set up with the A/C and rear window defroster for 10 minutes. I drove the car and everything settled down just fine. I drove the car a couple of days later and got the jumpy idle and Cruz thing back again. now today the car ran flawlessly. so in a couple of days I'll try it again and see how it works. in the next few weeks I am going in for a complete tune with a wide band and data logic so I hope these problems will be resolved.

Jeff