Car Wont Start With Powerfc Pro

[Hi5]

Hi all

I've just installed a Power FC pro (RB251PRO) for my R33 GTST. it's the correct model as far as I can tell.

The hand commander fires up and doesnt hang or anything. There are no errors in the sensor screen. I've turned the boost controller off in the HC.

When I switch to ignition, my fuel pump doesnt prime, and if i crank it it doesnt fire. Replacing it with the stock ECU and fuel pump primes, and it fires up.

Anyone have any ideas ? I'd be really gutted if i cant use this ECU

[d00dz]

Check fuses under the dash, boot and bonet.

Also have a read of Paul's PFC guide -> http://www.skylinesaustralia.com/forums/in...showtopic=64201

[Hi5]

I will check the fuses anyway, but as above, when i replace the ECU with the stock one, it fires up as normal.

I've looked at paul's guide to no avail

I'm stumped

[BAMR33]

Sounds like someone has sold you a faulty PFC knowingly.

[Hi5]

could it be a dodgy ground or power feed? and maybe the powerfc is more sensitive to it than the stock ecu ? :S

[justin911]

did you try put that special fuse in that paul talks about in the faq??

[Hi5]

i already have that fuse and it isnt blown :S

[Hi5]

this is from the pfc faq, and that the f/p is checked. on my car it isnt. can anyone verify that this comes on with ignition (but not cranked). My fuel pump doesnt prime with the pfc plugged in.

[justin911]

i had a look at mine just now... i dont have the F/P light greyed out until i start the engine... also, the O2H light on mine isnt greyed out either.

i think the pic from the faq is when the engine has started..

[Hi5]

ok thanks

argh.

[justin911]

i dont no if this is a good or bad idea.. but i did it when i had some fuel pump issues recently, she wouldnt prime etc.. i dont wana see any tears if anything blows up or something though

i grounded the neg wire (blue wire if i recall correctly) on the fuel pump connector in the boot and it seemed to bypass the ecu controlling it and make it work It was like doing that mod people do to make it run at full voltage or woteva.

[Hi5]

thing is, the engine wont fire up either, and it should at least once with the fuel in the system?

if i plug in stock ecu it works fine

[Beer Baron]

could it be a dodgy ground or power feed? and maybe the powerfc is more sensitive to it than the stock ecu ? :S

yes. i've seen this a lot of times. the PFC seems much more sensitve to a good power feed and good earth than the stock ecu. so check your power feed to the ECU, and maybe check your grounds too. or even tee in another ground and run it to a suitable spot.

[Hi5]

I wired in my previous SAFC and if im honest my wiring is a bit iffy at best of times. I'll give it a try. Cheers

[Hi5]

i dont no if this is a good or bad idea.. but i did it when i had some fuel pump issues recently, she wouldnt prime etc.. i dont wana see any tears if anything blows up or something though

i grounded the neg wire (blue wire if i recall correctly) on the fuel pump connector in the boot and it seemed to bypass the ecu controlling it and make it work It was like doing that mod people do to make it run at full voltage or woteva.

well, i just spoke to the guy that sold me it. He had it in his 200SX with rb25det dropped in, and he says he had his fuel pump hard wired into the ignition, just as above!

however, I'm just wondering if there is an option perhaps to make the PFC disable/enable the fuel pump control as it seems a bit odd still.

[Hi5]

is it possible that the pro simply doesnt control the fuel pump? as it's designed for drag use apexi might of presumed the fuel pump would be hard wired?

[paulr33]

its no different to the normal powerfc so just debug as if it were a normal PFC

can you post up what your sensor / sw check looks like?

did you do factory reset?

any of the sensor names in BLACK highlight (in sensor sw check)

do any switches (in sensor sw check) turn on (black dot) if you try and crank it ?

[Hi5]

its no different to the normal powerfc so just debug as if it were a normal PFC

can you post up what your sensor / sw check looks like?

did you do factory reset?

any of the sensor names in BLACK highlight (in sensor sw check)

do any switches (in sensor sw check) turn on (black dot) if you try and crank it ?

I will take a pic of the screen when I try it again today. I'm going to a friends to go over my ecu loom to check the power and grounding.

I did do a factory reset, and i then turned off the boost control. I checked the AFM type and it is set to normal.

none of the names were highlighted in black in the sensor sw check.

[Hi5]

Right,

the fuel pump sensor changes to a black dot in the sensor screen when you try to start the car, so it must think that it is activating the fuel pump (but it isnt).

today I grounded the fuel pump so it always pumping when the ignition is on, and the car started. So this means that the fuel pump circuit in the PFC is faulty?

I let it idle for 10 mins, then 10 mins with rear window heater on, then 10 mins with A/C on. However now when i start it up, it sometimes hunts for a few seconds, and also the idle is high (1100rpm). If I drop the clutch and let the revs drop while driving they take a while to go below 1100rpm, and if changing up this can sometimes pull the car forward, so isnt ideal. I can get used to it but maybe someone knows a solution?

would anyone know where the resistors etc are for the fuel circuit on the pfc? I opened it up and the PCB looks fine, no burnt tracks or anything.

finally, will i do any harm running the fuel pump like this. It is an R34 GTR fuel pump, and is 2 stage. It is quite loud anyway, but on idle it used to drop to lower pressure and was a little quieter. Now it is is runing high pressure constantly, will this do any harm?

cheers

adam

[Hi5]

oh yea, plugged the pfc into a friends gtst and it showed the same problem so is pretty definately the pfc at fault