kaduku

Ive had this issue intermittently, Where itll stall while driving. Then itll start back up.then one day pulling out of a parts store, it died. And refuse to start but keeps cranking. Towed it home.Replaced my fuel pump. No avail. +B with key to on is showing .25 volts. If memory serves me shouldnt it be at 12+ volts? Ive tried jumping +B amd FP, and still nothing. I check for power on the fuses and efi relay and all is good. Check for power in the trunk through the fuel pump control with the green wire and red/black and have no power. Im stumped! Thanks in advance.

Ps. I did rub through my fender harness but got that squared away and tucked. Whats the yellow insulated wire for? It rub and exposed the wiring. I fixed it and covered it.

dicer

Sorry I don't know 94's. On a 90 you would have to do the jumper thing before any power would be seen at the pump. When having what is thought to be fuel pump problems, things like fuel pump relay and resistor and other related power supplys should be eliminated before attacking the fuel pump. I think the average fuel pump lasts way over 300,000 miles.
The fuel pump should only run when initially turning key to start, to charge fuel rail. If no rpm signal showing it started then no power to the pump. So what else did you check? Trouble shooting can't be a fixation deal, where you think its this or that. Did you check for spark? Did you check fuel pressure?

Yamae

Sounds like an inhibiting mode to me.

Those who don't know the detail often just jump +B and FP and say nothing happens. You'd better to check that it is caused by the inhibit mode or not.

In this mode, the +B supply to the fuel pump is disabled by the ECU in 3 or 5 seconds after the starter is engaged. In this situation, the engine starts but stops quickly or no engine starts at all.

dicer

Yamae, if the ecu goes into that inhibit mode, what resets it? Is it just turn off the key? Or disconnect the battery?

Yamae

Didn't you see what I have written?
" the ECU stops the fuel supply opening the circuit opening relay"

Incidentally, what does the circuit opening relay do, dicer?
Do you remember it? I have informed you about it.

dicer

What are those conditions? There are 4 below. When one or more of these are detected, the ECU stops the fuel supply opening the circuit opening relay.
1, No signal from the MAF for more than 3 seconds.
2, No signal from the crank position sensor for more than 5 seconds.
3, No signal from the cam position sensor for more than 5 seconds.
4, No IGF signal from the igniter for more than 3 seconds although the IGT signal is sent.