Fuel Pump stays on & hesitation under load and idle

[Hill185]

Thx Frisky

[friskyfrankie]

No problem - really hope it helps and just get back to us with the happy results!

[sly]

Sounds like the relay is bypassed. The relay socket should have constant hot so if it's bypassed, that would cause constant hot direct to the pump.

[massacre]

Sounds like the relay is bypassed. The relay socket should have constant hot so if it's bypassed, that would cause constant hot direct to the pump.

Agreed. Like the relay is jumped out.

[gadget73]

yeah something is shorted. Only place a hot and the fuel pump feed should be anywhere close together is in the socket itself but someone could have bridged those. Likely if its going to exist, it will be right under the relay in the socket area or very close to it.


if the ECM was b0rked, it would still stop the pump if you pulled the relay. the only thing the ECM can do is ground one pin of the fuel pump relay. If the relay is out, whatever might be happening with the ECM or wiring to/from it will not matter. Someone has jacked it up on the power feed side.

[Hill185]

GOT IT. Whoever said fuel pump was jumped was correct. While attempting to fix the stalling out poor running issue, I changed the ignition control module and I screwed up the timing. The car was towed to a local mechanic shop to get the timing issue fixed. Well I called them to ask them if they altered the fuel pump at the shop and the manager seemed confused. However today while tracing wires I found this wire sticking out of a harness(see picture). I pulled it out and the fuel pump shut off as intended. Thanks so much for all your input guys huge help.

Fuel pump is sorted out, but still runs rough so I’ll still continue to search for vacuum leaks.

[sly]

That's the fuel system priming port. You should ask for the plug back that fills that hole so the connectors don't get full of dirt.

[massacre]

That's the fuel system priming port. You should ask for the plug back that fills that hole so the connectors don't get full of dirt.

Great idea ^^^

[sly]

Just remembered... that plug may be there on the inner fender as I think it has a push in fastener (christmas tree) on the back that holds it down. I'll try to look at my wife's car when I get home as it has the same thing.

[sly]

Here's what it looks like...

[gadget73]

so does that jump the +12v contacts then ? The one in the self-test connector grounds the relay same as the ECM does, so it won't run the pump with no relay installed.

[sly]

Yeah... this one jumps the 12V hot to the wire to the pump. Can be run when the car is off. A service port so to speak.

[gadget73]

thats actually quite useful. The old style one had to have the key turned on for that. No +12v to the relay coil without the ECM relay pulled.

[Hill185]

Unfortunately shop must have lost the plug to that fuel pump service port so I capped it with a generic plug for now. Thank for all the reply’s, very helpful.