Rb26 Pfc And Harness On Rb25 Wont Run Right

[stricnynel0s]

ok i am running a rb26 pfc on a rb25, the afm is wired in parallel to a single z32 afm, and the o2 sensors are wired in parellel. my first issue is that when my car ran it idled at around 1500 rpm but it was constant, for some odd reason it perfered to be set on STANDARD r33 and not vg30 afm, now the car would run though. than for some reason the fuel pump stopped getting power so i decided to hard wire it in with a relay, the signal is coming from the radio harness, so when i turn the acc on the fuel pump will stay on, not llike normal where it primes for a second than stops and now when i i try and start it it tries to rev but than it dies out fast, i know the car is super rich since i am using a rb26 harness and the 440s on a single rb25 turbo so i tried to lower the fuel pressure but my gauge broke so i stopped, i tried reseting the pfc and doing the initial startup for idle but it dies out immediabely, i have no boost leaks either, i am stumped how can i lean out the fuel and what can i do to make it idle again, should i put the car in closed loop ? also i did disable the boost control feature too i have a wideband 02 also, and the car never goes 11 afr

[zebra]

From memory you can't wire the AFMs in parrallel and you need a SAFC to alter the signal...If I were you I would get 2 standard GTR AFMs and go from there

[SLAPS]

Easy fix..

Set it for VG30 and set airflow correction to 50% for all voltages.

That will get it running well enough to just need a 'slight' map tidy up.

Its worth while getting the datalogit on to it to zero out the inlet air temp correction.

Edited July 8, 2009 by SLAPS

[stricnynel0s]

Easy fix..

Set it for VG30 and set airflow correction to 50% for all voltages.

That will get it running well enough to just need a 'slight' map tidy up.

Its worth while getting the datalogit on to it to zero out the inlet air temp correction.

i actually have the capability to do the ait sensor since i have one i just need to install it before the TB, but why wouldi set the voltage to 50% ? gunna try it just curious why that would fix it, also i can wire the afms parallel, all he pfc does is take the value and divide by two, it does the same thing with the 02 sensors

[flame_this]

im trying to do this atm, having the same problem.

02 sensor averages the sensors so splicing them if fine.

but unsure of this: gtr afm signals are added so for a 25 you splice the 1 signal to the two afm pins (so it doesnt run on knock map and get correct ecu load) but doing this effectively tells the 26 ecu u are taking in twice the air so to correct this turn the voltage down to %50 on fc edit (will also correct ecu idle load point).

CAN SOMEONE CONFIRM THAT WHOS DONE THE CONVERSION?

my issue is when i do that i cant get enough fuel in around load point 7 and beyond and just leans out no matter how much correction i have in.

[GTSBoy]

I think that's because the VQ curve is not a straight line. So just halving the voltage returned by the AFM is not actually halving the "signal". The VQ map is a smooth curve, but if you squint when you look at it, you could approximate it by a line at one slope below 25% load, and another steeper line above 25% load.

If you just halve the voltages, you can try to get it right for one side of that straight line pair, or the other side, but not both.

I would have thought, seeing that the PFC just adds the AFM readings together, that it would be fine to just run 1 AFM, get a zero reading for the other (or some low fixed voltage that you could arrange by just using a resistor to simulate it) and come out the other side correct. As long as the PFC doesn't freak from having proper readings on one AFM and bullshit reading on the other.