Hello everyone, my 89 6 spd is not running. So I took out the page in the FSM on the FP circuit. I put power to ALDL terminal g and the pump did not run. Then I took the connector at the tank apart and no power at the connector. I checked for and found 12 volts at circuit 340 the orange wire going into the oil pressure switch. I turned on the key and checked for voltage at the FP fuse. No voltage. Then I took the connector off the oil pressure switch/sender and jumped to connector. I got voltage at the fuse and the FP connector. So my question is if I jump the connector. When the car is off. Will the fuel pump be running? or will the fact that the key is off keep power from going to the fuel pump. . I'm on Guam ordering and receiving parts is at least three weeks. Sometimes I have to send them to my home and have them mailed to me from home.
I have replaced the OPS three or more times. Should I buy a new connector?
So I jumpered the connector and realized that the FP connector had power even when the key was off. so I figure the FP would run continuously if I did bypass the OP switch/sender. Any suggestions.

Thank you all

 

Yes, the pump will run continuously with the jumper in place. Circuit 340 is constant battery power through a fusible link.

 

EDIT/ADD: With the fuel pump jumpered at the oil pressure switch, does the engine start and run? If = NO, do you have spark? If = NO, you may have an ignition system problem such as Ignition Control Module or pick-up coil. If the ECM does not receive reference pulses, it will not turn on the fuel pump. << Check this first. Jumper the oil pressure switch and attempt to start it. If it starts, continue reading. If not, fix the ignition first.

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I think you have a bad fuel pump RELAY and possibly its connector is burned. Unplug the relay and inspect. (It is mounted to the driver side of the wiper motor. 5 wires: 2 reds, orn, blk/wht, grn/wht.) (There may be a CAGS relay mounted adjacent to the fuel pump relay. I'm not sure where the CAGS relay is in an 89. But they may be the same relay, and you can substitute. Compare the part numbers on the relays. If the same, you don't have to wait for a replacement on Guam.)

When you jumper the oil pressure switch, that bypasses the relay and its connections. Because the pump runs, the wiring through the fuse, to the rear, and the pump itself is good.

When you put 12 Volts on Terminal G, that power goes through the relay's Normally Closed contacts. The output wire on the relay is the Red wire at Cavity E. Because there is no power at the fuse with 12 Volts on G, I suspect that the connection in Cavity E is burned or bad. Check the connection. Also check that jumping A (orange) to E (the larger red) makes the pump run. It should.

Just "turning on the key" only runs the pump for a couple of seconds, then if the ECM doesn't see reference pulses indicating the engine is turning, it stops. So you will only hear the pump, or see voltage for a couple of seconds after the key is turned ON.

If the relay or its connections are the fault, which I believe to be the case here, the oil pressure switch should turn on the pump after a few seconds of cranking to develop oil pressure, and the engine should start. Because yours doesn't, I suspect that the oil pressure switch is also faulty.

Considering the lead times to obtain replacement parts on Guam, I would order a new relay, its pigtail and and oil pressure switch/sender. That should get you going.

 

Well the condition exists with the relay that is in the car and a new relay. CAGS relay? What is this. I will take a look at the wiring that goes into the relay. Thank you for the suggestions.

 

I thought it would run full time if I jumped the OPS. And it did. It seems like it is something in the FP relay wiring. I actually have a new FP relay. I'm going to look at the wiring, again. LoL
Thank you

 

Computer Aided Gear Shift (CAGS). Also know as Skip-Shift or 1 to 4. It was incorporated into the ZF 6-Speed. Very likely disabeled in your car many years ago, but the hardware is probably still present.