Mechanics

FUEL PUMP /FUEL PUMP RELAY

1990 Lincoln Town Car

Electrical problem
1990 Lincoln Town Car V8 Two Wheel Drive Automatic 145000 miles

Hello,
My fuel pump was not engaging during start up. 12v all the way to relay (30contact), 6.3v relay(87contact) and 5.2v at pump . I powered the pump directly from the battery and it works. The relay is also good, I took the same jumper I use from the pump to the battery and put it behind the relay at (87contact) and pump worked find. My question is, is it ok to bypass the fuel pump prime connector(use for factory scans) and the electronic engine control module? Both of these devices are after the relay on the same wire pk/bk leading to the pump.

Thanks
Avatar
Tigerlily
September 10, 2009.



Try this and tell me if it works-At the fuel pump relay connector socket find the red and yellow wire make sure it has power jumper it to the pink and black

Rasmataz
Sep 10, 2009.
Hello,
I tried, still not getting 12v after the relay. The pk/bk wire has resistance somewhere in the wiring after the relay(difficult to find without pulling the dash and carpet) I ran a new wire from the pump to the relay at 87(connector), cleared my fuel lines of air and the car runs great. Just afraid this might cause a future problem, because I bypassed the fuel pump prime connector and electronic engine control module. These two devices come after the relay on the pk/bk wire, on the wiring diagram.

Thanks

Tiny
Tigerlily
Sep 10, 2009.
Fuse T and fuse no. 13 powers the EEC power relay from there it goes to the computer KAPWR circuit

What color wire is at No. 87

Check power at the fuel pump cut off switch red wire

Unable to read EWD below give me your email addy and I'll send it thru there.


http://www.2carpros.com/forum/automotive_pictures/12900_fuel_pump_circuit_5.jpg


Rasmataz
Sep 10, 2009.
Good morning,
Pk/Bk is the color of the wire coming out of contact 87 on the fuel pump relay.

The pump cut off switch has power at red wire, 12.4v key on.

No, I can not see the diagram you sent. I have to have 10 posted in order to PM you.

I don't think the Pk/Bk wire powers the EEC, it may just sent a signal. Car still runs great and the fuel mileage has increased back to normal. (Normal fuel mileage per tank is around 400miles or more on the display, before I was just getting 310mile per tank.)

Thanks

Tiny
Tigerlily
Sep 11, 2009.
When you turn key On-Do you have power at the red and yellow wire on the fuel pump relay socket-If not you have an open with this wire between the relay and inertia fuel cut switch or the inertia switch itself-You said you have power on the red wire at the inertia switch if so and the fuel pump relay is good the fuel pump should come on.

The pink and black wire doesn't power the EEC relay. It is the wire that powers the fuel pump when fuel pump relay is energized

Rasmataz
Sep 11, 2009.
This forum has saved me a lot of time and money. If I would have started here, this would have been a $20 to $30 fix, instead of a $150.00: ( Well lesson learned, now I know how to change a fuel pump: ) Thanks!

Tiny
Tigerlily
Sep 11, 2009.