Engine Fuel not pumping

[AeroCoupe]

Good call man. Completely forgot about that connector.

 

[Creomod]

A

I don't think anyone has said it yet, but a couple years ago I had similar fuel pump issues where it would just quit out of nowhere. I did the same fuel pump relay replacement, jumpered the pump on full time to test and everything would work. I would put the relay back in and all good for a while. Then out of the blue it would quit again.

For me, it turned out to be the connector in the driver side kick panel area. The power wire for the relay goes through this connector. What I found was the female pins had opened up and were not making good consistent contact with the male pin on the other side of the connector. A simple tap of your foot against the kick panel could cause the fuel pump to lose power - not a fault with the relay, just no power to the relay. To fix it I used a small precision screw driver to bend the two halves of the female pins inward and cleaned both sides of the connector. I haven't had an issue since.

I had to do the same thing with the pins on my power window switches as these were intermittent at times too. Worked great there as well.

hhhh that’s a good one, my car starts,runs but runs super ragged. Then the cel light comes on and stays on till I get home that’s if it dosent turn off and then when I’m looking I get the mo fuel on the gauge. I saw a video about the ecu and the parts of the fuel that go out and I just assumed it was just the 3 capacitors but I see they have a transistor for each fuel injector so maybe the ecu or injectors?

 

[AeroCoupe]

Just send the ECU off and get it gone through. At least you will know it’s 100% after that and they replace and upgrade parts on every one I’ve seen sent in.

 

[Shakerhood]

The ECU does a 2 second prime on key on with PIP signal, jumping the relay commands it on bypassing the ECU. Usually when it's an ECU failure due to hardware (swollen caps) the pump runs continuous. I believe the outside cap (the one near the edge of the board) is responsible for the pump circuit so when it goes the pump runs. There is also a fuel pump transistor that rarely fails.


Don't rule out corrected connections of brittle wiring as well here.

When my car wouldn't start last Summer, I traced it to the ECU not sending a Ground signal to the Relay. During the EEC rebuild process they sent me an email stating that it had an extremely rare failure and didn't even keep the part in stock, guess it was that transistor.

 

[Mindseye007]

I don't think anyone has said it yet, but a couple years ago I had similar fuel pump issues where it would just quit out of nowhere. I did the same fuel pump relay replacement, jumpered the pump on full time to test and everything would work. I would put the relay back in and all good for a while. Then out of the blue it would quit again.

For me, it turned out to be the connector in the driver side kick panel area. The power wire for the relay goes through this connector. What I found was the female pins had opened up and were not making good consistent contact with the male pin on the other side of the connector. A simple tap of your foot against the kick panel could cause the fuel pump to lose power - not a fault with the relay, just no power to the relay. To fix it I used a small precision screw driver to bend the two halves of the female pins inward and cleaned both sides of the connector. I haven't had an issue since.

I had to do the same thing with the pins on my power window switches as these were intermittent at times too. Worked great there as well.

do you know who sells that black connector in the drivers kick panel ? i had a similar issue with my 91 5.0 coupe 2 weeks ago and the mechanic said the black connector plug was melting some how and he bypassed one wire from the black plug the pink with black tracer wire rewired it and the fuel pump fired up with the key on . I am running a aeromotive 340 lph fuel pump it was installed about 7 years ago I dont daily drive it only a few days a week so it lasted a long time but t i think i should have not upgraded for my current setup and i only have full length headers and an explorer intake with 70 mm TB , 76 mm mas air stock 19lb injectors was trying to save for a v3 blower but no go yet think I'm going to down grade the pump to a 190 lph walbro . what do you and others think?

 

[Mindseye007]

Just send the ECU off and get it gone through. At least you will know it’s 100% after that and they replace and upgrade parts on every one I’ve seen sent in.

10 years and still blowing strong ? oh AeroCoupe ? does that have something to do with you changing and adding it to my profile ??? lol

 

[AeroCoupe]

Nope. I am not a mod so I cannot do those kinds of things....but Noobz and Mustang5L5 can and we like to point that stuff out for them and your are welcome!

The factory wiring is good to boarder line for a 255 lph pump. A 340 lph is really pushing it so either downsize the pump or wire a relay in and take the load off the factory wiring to the pump side of the connector just behind the bumper cover and at the back of the tank.

 

[Mindseye007]

Nope. I am not a mod so I cannot do those kinds of things....but Noobz and Mustang5L5 can and we like to point that stuff out for them and your are welcome!

The factory wiring is good to boarder line for a 255 lph pump. A 340 lph is really pushing it so either downsize the pump or wire a relay in and take the load off the factory wiring to the pump side of the connector just behind the bumper cover and at the back of the tank.

Ok Noobz is the prime suspect then I am going to put an APB out on Noobz.

 

[AeroCoupe]

Yeah look at my CT…‍‍‍

I think I have myself and Mustang5L5 to thank for it.

 

[Noobz347]

Ok Noobz is the prime suspect then I am going to put an APB out on Noobz.

How may I assist you my son?

 

[AeroCoupe]

You kill yourself don’t you?

 

[Noobz347]

You kill yourself don’t you?

I really do.