Having Issues with Fuel Pump not turning on

[influence]

Recently my car died (91 GT) had little less than quarter tank. I have been wanting to upgrade the fuel pump to a Walbro 255 and assumed this was the time.

Well did the whole replacement and the pump still wont turn on. I ran a lead straight to tthe battery and the pump turned on but then winded out and sounded like it was having trouble(I stopped this immediately after this happened.

My issue is I cant get the pump to start up regularly. I have no idea what it is, I read a few things about fuseable links but Im lost. Does anybody know what this is or why.

Thanks in advance

 

[HISSIN50]

If the pump sounded strange when you ran a jumper wire, this would concern me. I would want to know why the pump is acting up when powered with the jumper. Once that's copacetic, then address the factory wiring issues, if any.

 

[influence]

well the car wasnt running when I did this, I just hooked it up to see if it worked in the tank with fuel running through it.

I dont know why but before this happened the old pump wouldnt even start up after the car died

 

[1993SSP]

What year model is your car? I know on my 91 model there is a fuel pump relay under the seat, also there is a relay on the right side of the dash located above the computer. Also there is a fusible link under the hood for the fuel pump relay. Most likely one of these is your problem. The fuse link for the relay connects to the starter solenoid, check all of those first then work your way towards the relay's.

 

[influence]

j

Is there anyway you can tell me exactly where tehse are all located except the one under the seat. and what exactly does a fuseable link look like. Car is a 1991 5.0 GT

Thanks in Advance

Do you think the initial sound of the pump coming on and then stalling out was that the fuel lines are full of pressure?

 

[1993SSP]

If you hot wired the pump it will run constantly, but when you turn the key to "on" and do not try to start the car and you hear the pump prime up for a moment that is completely normal.


The fusible links will be black in color and a little over an inch long. They will come off one of the larger terminals on the solenoid, they should have a firm feel to them, if they feel real mushy or you can tell by the way they look that they have been melted most likely that could be a problem.


As for the relay on the passenger side of the dash, it's above the computer and it can be a pain to change. Just take your time looking and you will find it.

 

[1990Coupe]

There is only one fuel pump relay.

the relay by the computer is the ECU relay and does not work with the fuel pump circuit. You can check for 12v's coming into your inertia switch in the rear of the car. If you don't have any voltage there it could be the relay. if you have no voltage to the relay, then its your fuse link. It lives over by the starter solenoid, you can check that too.

 

[influence]

But if I hotwired the pump to a constant 12v source when the fuel system is closed(car off fuel pump hooked up in car) cant the pump only pump so much until it reaches the FPR or injectors? This would make the pump lag a bit since the lines are full and have no where for the fuel to go?

Stilll lost on the fuseable links is it just the piece of plastic that connects wires together? They are everywhere on the car? I tried tracking from the starter ( this is the wire that powers up the starter) but you cant even see or find that wire?

 

[87WhiteStang1]

first of all check the inertia switch if you havnt yet? the fuseable link is right near the end of the wire where it connects to the starter solenoid, it is a small black box made of rubber..and i believe that the wire for the fuel pump is green. if it seems like it may be blown then you can cut out the link and hook the wire straight to the solenoid and try it then.

 

[influence]

fuseable links good Pink w Black Stripe
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tested with volt meter getting voltage after fuseable link
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No power at inertia switch (button is down position)
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No power at relay
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Check ECU Harness wire (lt blue w/orange stripe) GOOD
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Fuse is good #18 Spot
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still no power to fuel pump/inertia switch or relay

 

[1993SSP]

I have read my ford tech manual, it says if there is no voltage at the FP relay under the seat and all fuses are good as well as the fusible link to check the EEC relay power wire, it also says to check the ground on the EEC relay if you do have power to the EEC relay.

My guess is you either are getting no power to the EEC relay, bad ground or it could simply be that the relay itself has gone bad.

 

[influence]

okay checked the ECC Realy above the Computer (ignition to on position) there is power.

Not sure on the ground Where would I look?

 

[1993SSP]

one of the wires on the EEC relay is a ground. There has to be a simple reason why you are not getting any voltage to the fuel pump relay under the seat. The only thing I can think of would be either the fusible linke or a blown fuse in the fuse box under the dash

This manual also mentions a IRCM (intergrated relay control module) for fuel pump control, says it is mounted on the upper radiator support bracket, I have never seen one of these on a car but that may be a possibility that you have one on yours

even though you are getting power to the EEC relay it could still be faulty could'nt it?? Could be that it's getting power in but not putting any power out

 

[HISSIN50]

GT's dont use an IRCM.

Assuming you have EEC power output, if you do not have power at either side of the inertia switch (but you have it leaving the normally open terminal of the FP relay), you'll have to trace it backwards to find the open in the wire. Or run a new wire.

When you note that a relay has power, you have to note if it has power out of the normally open terminal, power into the common terminal, or power to the relay coil.

 

[influence]

i ran a loop wire in the fuel pump test circuit and tested the green and yellow wire into the fuel pump relay no power there or the inertia switch.

I tested the blue orange wire at the fuel pump relay and there is power.

i have 3 different fuel pump relays none of which seem to be working or not showing power on the green yellow?

I had an extra ECU that I know works still nothing.

Still trying to figure this out and am lost opened up all the wires under the carpet and traced stuff it all looks good, including the fuseable links and fuses the pink black wire has power all the way to the fuel pump realy as well.

one thing I am trying to figure out is testing number 22 pin with the computer unplugged it says to plug in test light to positive then jumper pin 22 to ground and the test lamp should glow.

Does this mean just leave the test light open on the positive and then run a seperate wire from 22 to ground or stick the other end of the test light in 22?

I tried putting test light on battery and ground out pin22 no light showed up?

So if I did it right then I dont have a signal I believe from the ECU to the Fuel Pump Relay....if this is true I dunno what to do because it is impossible to trace that crap without ripping out my entire dash...

 

[HISSIN50]

Blue/or should not show power. It is a ground pathway for the FP relay's coil.


Properly ground the relay coil wire for the FP relay so you can do dignostics.

WHen you turn the key on, you should see the other 3 wires showing 12 volts. If you do not, tell us which one(s) doesn't.

You should have pink/blk showing constant 12 volts.
Red and dk green/yellow should show 12 volts with the key on and the relay coil's negative terminal grounded.

 

[influence]

Fixed

Holy....Crap....Fixed it

It was the Fuse LInk to the ECU................

and the Fuel Pump Relay............................

and the ECC Relay......................................

I tested all of those especially the damn Fuselink had power way after the link, but there was a little burn mark in the wire(not the link) so when I pulled it the wire fell apart............unbelievable.

Well I would to thank everyone for their input and help on the matter, I couldnt have figured it out without all your help...............:SNSign:

 

[sicstang]

I know this is older thread but exact problem i am having. i have 12 volts on blue/orange wire and no power on the other 3. i just put new relay on it today with no luck of the fuel pump cutting on. thanks in advance for any help. oh i checked the fusible link by the starter solenoid and it test good.

 

[jrichker]

I know this is older thread but exact problem i am having. i have 12 volts on blue/orange wire and no power on the other 3. i just put new relay on it today with no luck of the fuel pump cutting on. thanks in advance for any help. oh i checked the fusible link by the starter solenoid and it test good.

Start your own thread with the car year and mods listed, and I will try to help you.