09gugan

hi all
i have a 94 limited edition 4.0l petrol auto and im having problems starting my jeep...its cranking over im getting a spark but will not start the fuel pump is not kicking in ive been told it might be the fuel pump or crankshaft sensor but i dont want to be spending £££ to find out it is some thing else ive checked all fuses and relays and them seem good any help and advice and i would be really gratefull
cheers
ryan

ezab

I would say it is more than likely a bad fuel pump.

09gugan

ok cheers ezab looks like ebay is getting another visit off me lol

Frostracing

Definitely check the voltage to the pump before buying anything. There are a couple things that can go bad and keep your pump from getting power. I unplugged the connector at the fuel pump, set my voltmeter on rear tire and grounded the black wire. Then I checked each prong on the connector coming from the car with the red wire by turning the key just to the on position where it primes the engine. The prong for the fuel gauge should see 5 or less volts if I remember correctly and the one for the fuel pump should see about 12. As long as you have a voltmeter this should only take 5 minutes or less. And remember to turn the key off than on for each prong because the pump only gets power for a couple seconds each time just to prime the engine.

09gugan

i just put a live feed on to the pump and still no power up ???

ezab

Then you should replace the pump.

Frostracing

That sucks, you probably need a pump than but I would definitely check the wiring going in to it first. What would be worse than the situation your in now is putting in a new pump, hooking it up and not having it work. They're not returnable once used at my local store. Are you sure you put the live feed on the +POS pump prong and not the -NEG or fuel sending unit one?

09gugan

yeah my pal done it and he knows his way around a car but does not want to say it is defo the pump just incase its not and ill be slagging him off for wasting my money lol looks like a new pump is gonna be needed
cheers all

freegdr

when you tested the pump did you also use a ground wire when you hooked up the live feed you have to have both

09gugan

he had 2 wires running on it so i presume so gonna change the pump if it dont sort the problem out ill look at the crank sensor and if still no joy ill torch the damn thing lol

freegdr

there are three to the pump one is for the gas gauge two for pump when you pullit ot check it again before you take the old one out of the box

09gugan

will do cheers as soon as i get it sorted ill post and let you know what the problem was

freegdr

there one more thing i see no body said any thing about do you have a white cermaic thing like this power to the pump feed thru it check for curren with key on at both sides its on the driver fender under the hood

freegdr

looks like this

09gugan

well i changed the pump and still the same problem..it turns out it was my electronic feedback system which is part of the lpg conversion i just run a wire and bypassed it and it fired straight up thanks for the help...and i hope it helps others out in the future