Power FC driving me nuts, need experts

[240zdan]

I have a Power FC D jetro with dual map sensors tapped into the balance tube. Running 550cc Evo Injectors with an aeromotive FPR. O2 sensors turned off, Idle IG on. RB26, splitfire coilpacks, new plugs. Walbro 255
Problems are as follows:

AFRS change with voltage drop. I will tune the idle afr to 15.0:1 with the headlights/heater on, when I turn off the accesories AFR changes leaner almost one full point (16.0:1)
This is extremely frustrating as creates problem number two
It WONT idle. It will sometimes drop to a stable 950rpm idle but for the most part it will idle at 1050 or above. This drives me nuts as the power fc pulls tons of timing to try to reduce the idle making for a very erratic running engine. It will idle decentley with the accesories on. It still idles no where near the target RPM. The only way I can temporarily solve this is by raising the idle parameter to 1100 then bring it back down to 800 or so, then the idle will drop. As soon as I blip the throttle the idle will resume back to 1100 or so. TPS voltage is at .45-.46 at idle and idle circuit is on with throttle off.

This is in a swapped car so not too sure if the ELD is on. donno if that makes a difference. Also no VSS
I remeber on hondas you could tune the injector batterey offsets (each type of injectors had different offsets) but the POwer FC obviously doesnt have that feature.

Please help me out guys, I paid $1500 for a stupid standalone that runs the car worse than if I had a carb on it.

Cliffnotes: AFRS change with electrical load
Idle will stay at 1100rpm unless manually adjusted up then back down in rev/idle parameters

[Carl H]

you need to check several things:
1) voltage of the battery and operating voltage of the alternator - weak battery will cause the system to work harder and thus cause issues...a bad alternator can also cause voltage issues. use the pfc HC to check running voltages or tag it directly at the battery. if the alternator is bad, fit a quest alt (110a)
2) idle switch not engaging - rb26 requires that the idle switch to be engaged with the throttle closed to shift the ecu to the idle parameters...if its not engaging it wont shift logic. typical symptoms are a hunting idle and/or refusal to idle properly.
3) itb blades - itbs may need to be resync'ed for proper operation, refer to the FSM or use a set of carb balancers to do it.

[240zdan]

Voltage of the alternator: I get a steady 14 volts with no accesories, and lowest ill see is 12.5 volts with heat, headlights, wiper, fan etc on.
Idle circuit: Like I said idle circuit is lit up
Throttles: This is one thing im not sure about. I will have to check the sync.

Another question: When I unplug the Lower engine harness, idle doesnt change. Screwing in the IACV adjustment screw, still high idle.
Also I heard there is another cold start valve located somewhere under the throttle bodies which is really hard to get to, could this be causing a high idle issue?

Im pretty convinved now that the issue isnt even power FC, I think its either incorrect TB adjustment or Cold start valve. Anyone ever get to this without removing the TBs?

[robbie2883]

do yourself a favor and invest in FC datalogit. the software inteface makes thing so much easier and unlocks alot of extra options in the pfc...including injector lag times vs battery voltage

[240zdan]

OKay so:
Air regulator wasnt hooked up, bypassed it for now and idle is stable
Datalogit is my next purchase.

Thanks for the help guys

[StricNyne]

toad8xu was selling one i think

[Carl H]

lol, was...john has it now.

[240zdan]

any place I can buy it? other then ebay

[gawdzilla]

that's strange that your air regulator solved it. that should just be for cold start.

anyway, i also had a similar problem which you may run into later.

when there is too much electrical load, my car idle rpm would bog a bit come close to stalling out. the biggest electrical load is my electric fans, so i wired another relay to also trigger the grounds for the a/c and the ps pump load pins on the ecu. now when my fans kick on, those two indicators trick the ecu to bump the idle higher to compensate for the additional electrical load.