1990 Chevy Lumina Euro 189Kmi. 3.1litre No Voltage Fuel Pump

BIGRODK

MEMBER
1990 CHEVROLET TRUCK

Car stalled on the wife the other day and thought it would be the fuel pump, but it wasn't. No voltage to pump. The fuse was fine and is getting the proper voltage. So, I traced the wiring from the fuel pump relay to the oil pressure sensor (orange wire) and traced the wiring from the oil pressure sensor to fuel pump (gray wire) & everything checks ok no breaks or bad connections. Checked the orange wire (12volt) out of the relay and no voltage, replaced relay with known good one and still no voltage. I Pulled the relay box and checked the connections under the relay all ok. Is there something I'm overlooking? When you turn on the ignition, the relay acts as it should. Clicks on for a couple seconds and then closes as it should. Where would the relay get the 12 volts for the orange wire from? I thought it would come directly from the fuse to the relay to the pressure switch to the fuel pump. Can I run a jumper to the Orange wire coming out of the relay going to the oil pressure switch to see if I can get power to the fuel pump without hurting anything?
Any help would be appreciated as I don't have much hair left anymore lol. Thanks

1 Reply

RLJ7132

MEMBER
5 POSTS

If the fuel pump relay closes for a few seconds when you turn the igniion switch to the on position and then opens again then you know that everything is good from under the dash and hood as far as fuses and relays.
The problem is probably betwen the relay and pump.
The repar manual for that vehicle should have a troubleshooting section under the fuel section that deals with jumping the fuel pump to see if it works.
On the 90-95 lumina apv, transports, silhoettes, you have to disconnect the electrical connetors under the car that go to the fuel pump by te tank. Disconnetth wire harness that comes out of the tank and goes into connects to frame. Connect 12 bolts battery voltage to the gray wire terminal and the black wire to ground. Make sure battery has a good charge. If the pump runs its ok then check all connections and wiring again. If it doesnt run it may need replacing. You have to drop the whole tank.
Make sure you continue to check your voltage on the hot wires. Let me know how you make out.