VR Fuel Pump issues?

[Brett_jjj]

The ECU has a limp home mode so the engine will still run if the ECU fails for whatever reason,thats why its called "limp home mode", and if the ECU fails for whatever reason, and cant supply power to switch the fuel pump relay, the oil pressure switch will still supply the fuel pump with power,(once the oil pressure is up enough to extinguish the oil pressure light on the dash)

EDIT: Heres a bit of info from delcohacking-

" If the ECM has a terminal failure where the software can no longer run, then limp home mode is invoked. This is controlled by a chip called the FMD (fuel modeling device), if the CPU fails to reset the watchdog timer, limp home mode takes over. The spark is controlled by the ignition module. There is a line called bypass mode, when this goes to 5v the ECM takes control of spark timing and dwell, when its grounded the ignition module controls spark timing. In limp home mode the spark is controlled by the ignition module only. In ignition module mode timing is fixed at the base spark advance, this is usually 10deg BTDC. "

The spark just comes from (and is controlled by) the DFI module or ignition module when running in limp home mode.

 

[savage1987]

I was aware of something like this existing for the Ecotec engines, but this is the first I've heard regarding the early V6. Do the 304 models share the same setup? I'd imagine they probably got it first, being a 'higher-spec' engine?

I guess people who wire in a new higher-amperage fuel pump from scratch interrupt this process in some way or other?

 

[jerzey1234555]

Just had my car repaired by a mechanic they changed the fuel pump and now it's all fixed apparently it was a faulty unit

 

[Arrowroot]

make sure there is 12v at the pump connector round white connector at the pump, also it "prims when the key is turned on so 12v will only be there for 30 sec or so. might need a seccond person. a test light might be ok but a multimeter would be better, and they also come in real handy for other jobs (approx 30bucks for a cheepie, i use a $250 at work but you dont need one that pricy).

next is the pump if the voltages are fine. stright forward job, just dont brake the return line off in the tank, other wise you wont be able to use the last 1/4 of a tank.

Mate the return line your talking about, has it got a black rubber line connected to it inside the tank, as thats the thing stopping me getting the old one out, if so how do they disconnect them without braking ??