You F%$#@ing thing

[Anthony Miller]

Swapped alternators, no mean feat let me tell you, now no fuel pump.....arrrgh!! any thoughts on how I may have cocked things up would be greatly appreciated, cheers

[colcol]

Not a lot of experience with electric fuel pumps,... so find out where the pump is, in tank, on top of tank, remote, find it and see if it is pulsing and making a noise, if not, then see if you have power at pump, if not check fuse, if fuse ok, check pump relay, for power in relay, it is usually #30, see if you have power there, then check power out, usually # 87, check for power there, if all good with 12 volts, then its usually a worn fuel pump, but these are usually a bosch unit, so they are available and not too expensive, my experience with electric pumps is basic to say the least, best of luck, Colin.

[colcol]

90's, 75's and 33's all had the same undersize ignition switches, that the contacts would burn and cause no ignition or fuel pump, but only intermittenly, something to look at if you don't have any luck, but do what Mick says 1st, but i don't know where the fuel pumps are located on 75's, it might be a jack up the car job or pull all the mats out of the boot to get to the fuel pump, Colin.

[colcol]

It must be old school, where it was mounted where you could get to it, piece of cake, jack up the car, and Bobs your Uncle, its all there to see, newer cars have the fuel pump mounted in the tank, where the fuel keeps it cool, [i am not making this up!], Colin.

[Anthony Miller]

Cheers guys, I jammed the afm flap open and switched on the ignition and could hear the fuel pump working. Usually when I turn on the ignition I can hear a different pump sound to the one I've just heard, 

[Joey]

It must be old school, where it was mounted where you could get to it, piece of cake, jack up the car, and Bobs your Uncle, its all there to see, newer cars have the fuel pump mounted in the tank, where the fuel keeps it cool, [i am not making this up!], Colin.

I assume this applies to most 90's commodores but from my experience as a poor P plater driving around a VS commodore with low fuel all the time burns out fuel pumps - because they overheated and parts of them melted!

[Anthony Miller]

No one shits me like I shit me , I must have bumped the wires that feed the sensor on the front of the thermostat housing when I changed alternators. These wires are fairly brittle and broke off and the ecu went full rich making the car an absolute bitch to start and run like a dog when it did. So.... nothing to do with the fuel pump but an electrical gremlin none the less   

[colcol]

Well at least it wasn't the intermitten problem of a dodgy ignition switch, or having to change the fuel pump, just think of it as a learning experience, something more to tuck away in the  brain for future reference, Colin.

[dfrye]

My previously totally reliable 90 is now doing the random die when hot routine that my last one did too. It is the same shit with no power to the fuel pump. I've now got a switch in the cabin to put 12v to the pink/white lead that drives the pump so when it dies I flick the switch and away we go. Dont know if it is the relay or the afm flap closed input that is the problem.

Does anyone know which pin I have to ground or jumper to take the afm flap sensor out of the equation? Is there a modern relay I can install as the original ones are no longer available?

//dean

[colcol]

The 90 has the same dodgy ignition switch as the 33, wire up a pilot light to your ignition on wire coming out of the switch, and when your car dies, see if the pilot light is on, this will indicate burnt contacts in ignition switch, this will rule in or out a faulty ignition switch, Colin.