ECU/fuel pump/injector question

[veilsideS14]

Hey all. I'm wondering if anyone knows the correlation between the ECU, fuel pump, and fuel injectors on a BCNR33 GTR engine. More specifically, if the ECU doesn't see any connection to a fuel pump, will it deactivate the injectors? (i.e. ECU doesn't sense fuel pump = ECU doesn't work the injectors?)

I know that like the Z32, the RB26 fuel pump is controlled by the ECU unlike the Silvia which is chassis powered. I was just wondering since it's ECU controlled, will it do funky things to the injectors if the ECU doesn't see a pump hooked up.

Thanks!

[FAST-DATSUN]

I belive all GTR RB26 motors all signal the fuel pump to cycle the pump to matain the fuel pressure.. Anybody know for sure???

[veilsideS14]

That is my understanding as well. The RB25 does NOT act like this though. On my Power FC, there are two switch signals for FP1 and FP2 which are for fuel pump 1 and 2. There are also pins located on the ECU for these "pumps" as well. The GTR only has 1 fuel pump from my knowledge so I don't know why it's broken down like this. Anyway, yes, the GTR ECU cycles the pump to maintain pressure unlike the 240 which runs the pump at 100% all the time.

[93semax]

AFAIK, the fuel pump is controlled by the fuel pump control modulator. pins 104 and 106 go to the FPCM, the fuel pump it's self is not directly connected to the ECU. However the ECU puts a ground to the FP relay with pin 18 i believe.

[veilsideS14]

Right, but my question is, if the FPCM isn't hooked up or utilized in any way because the pump is controlled by the chassis (240sx) and not via the ECU (RB26), will it cause the ECU to shut other things off like the fuel injectors? Thanks for the info guys!

[veilsideS14]

Well, I called McKinney and talked to Mack about this. All I can say is that the dudes at McKinney rock the house! I'm very appreciative of all the help they were willing to give a random dude like myself. Thanks Mack!

[Redline240]

so what was the solution?

[veilsideS14]

Apparently the power for the injectors does not go through the ECU as one would suspect due to the injector power and ground wires running to the ECU, but instead goes through the lower engine harness. Weird? Yes...definitely.

[Vrtgrumpy]

veilsideS14, glad to see you got everything running. Let us know how everything goes.

Send some pics when you get a chance. Anything else we can do let us know.....

Grumpy