Did it again.....

NOTSOFAST

Member
Ok, last month I changed out the fuel pump and it seems to have crapped out again. Or should I say, im not getting no fuel presseure (again). I can't hear pump cycle when key is in on position. I can hear fp relay click, but no pressure on fp gauge. fuse is good and getting 11.9 volts to rear. I just can't seem to remember what I did last month to get it to work. Im loosing my mind.....:p :wtf:
 

pacecarta

LOGGED OUT
Staff member
fuel in the tank ( sometimes its the simple stuff that is overlooked )
does the car start and run ..if so either the check valve at pump crapped out (over tightening clamp at pump can do that) or you need a new gauge
if it doesnt and gauge is acurate and pump ran but no pressure then the line in the tank popped or your fuel filter is plugged or could be water in the system and is frozen

now if pump isnt running you say you checked 12v at rear was that at the tank harness wire to the pump ,
not sure how you read 12v to the pump since it would only have 12v for a few seconds after key on unless you jump the fuel prime wire by alternator to a 12v source, are you sure you didnt check the pink wire that is the power for the fuel level sender, on the three pin plug that goes to tank theres (c) black on one end (ground), (b) pink in center (fuel sender) and the other end (A) tan /white is the fuel pump power

and a relay clicking does not indicate a working relay, only a working coil in the relay , the contacts still need to be clean and able to pass the supply current to the load. contacts go bad over time from arcing when the contacts touch .
 
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Nick Micale

Tech Advisor
Staff member
This is very simple to check and determine if it is an issue in the tank.

Disconnect the fuel pump factory connector, and then connect/jumper power and ground leads from a battery and the pump will run or not.

I have used Kirban's new hand-held jump start unit as a battery to trouble shoot this issue which is much easier running long positive and negative leads direct from the battery to eliminate any possible car wiring issue.

If the pump runs and no pressure is at the rail, the in-tank hose is probably leaking?
 

pacecarta

LOGGED OUT
Staff member
if pump doesnt run to trouble shoot ....
run 12v to the fuel prime behind the alternator , if you dont have the jumper that came with the hotwire kit the hood lamp wire will reach and will plug into fuel prime connector .... if plugging 12v into the prime connector makes the pump run the main fuel pump relay could be bad on passenger fender (or it lost the ground behind pass head)
if pump doesnt runs then keep prime wire connected and temporarily bypass the hotwire jumper harness ( relay) at the rear bumper , disconnect the hotwire at both ends and reconnect the factory connector directly to the tank connector , if it runs the hotwire relay needs to be replaced or has issues in the hotwire wiring

if it still doesnt work ... time to drop the tank (again)
 
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NOTSOFAST

Member
pacecarta, I did what you suggested, I ran the fp test wire to back of alt and can hear pump run.:) I will swhichout the fp relay and see if that works. :shame: will also check for loose ground wire. I won't touch fuel tank (if i have to) until my day off on wednesday. :(
 

Boost231

What's An Intercooler
Staff member
This is very simple to check and determine if it is an issue in the tank.

Disconnect the fuel pump factory connector, and then connect/jumper power and ground leads from a battery and the pump will run or not.

I have used Kirban's new hand-held jump start unit as a battery to trouble shoot this issue which is much easier running long positive and negative leads direct from the battery to eliminate any possible car wiring issue.

If the pump runs and no pressure is at the rail, the in-tank hose is probably leaking?
What happened when you short the Kirbans jumper box? Does it have a fail safe?
 
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