Problem with Fuel Pump Rewire

[Captain D]

I have a 92 GSX and while adding an afpr modification I had to disconnect the fuel pump. My car has a fuel pump rewire mod and when I went to take the fuel pump wire off the relay, I couldn't get the wire off because it was too crowded so I took off all the wires (big mistake). When I completed the afpr mod I reinstalled the fuel pump wires on the relay but it was dark and I may have put the wires on the wrong terminals. When I turned the key to the on position the pump would not come on. I disconnected all the wires on the relay again and checked the wiring. The power wire to the relay had power. The ground wire was good. The fuel pump wire and pump worked fine when I ran an external wire to the battery. The trigger wire did not have voltage. Is the trigger wire (black and white) suppose to have voltage when the key is on? What component does the trigger wire come from going to the relay? Is there a fuse or electrical component somewhere that I might have blown if I hooked up the wires on the relay incorrectly? I reconnected the wires on the relay (85 ground, 86 trigger, 30 battery, 87 fuel pump) and I still can't get the fuel pump to come on and still no voltage on the trigger wire. Any advice would be deeply appreciated. This car is used to drive to work so I need it back on the road as soon as possible. Thanks...................

 

[steve]

IIs the trigger wire (black and white) suppose to have voltage when the key is on? What component does the trigger wire come from going to the relay? Is there a fuse or electrical component somewhere that I might have blown if I hooked up the wires on the relay incorrectly?

When done typically, the trigger wire is the old power wire to the fuel pump that comes from the fuel pump side of the MPI relay. It doesn't turn on when you turn the ignition on but when you engage the starter or when the ECU is receiving signals from the CAS telling it that the engine is running.

The stock wiring ran the fuel pump power off the Ignition fuse on the battery positive terminal and you could blow that by connecting the "trigger" wire to the wrong place but I would expect to see other issues too considering how many other things use the same fuse.

Steve

 

[Captain D]

Thanks Steve, I fixed the problem. Unfortunately I am not sure exactly how I fixed it. I cut back the wires going to the relay with the exception of the battery wire and spliced in new wire and connectors. I hooked the wires up to the relay and cranked it up. It runs fine. Could it be that the relay is intermittenly inoperative? After I got it running I checked the voltge on the trigger wire and you are right, no voltage in the on position, only the start position. Thanks for the advice. One of the reasons I like owning an Eclipse is this forum. I know if I have a problem someone going to try and help me. Thanks.....

 

[steve]

Depending on which fuel pump your running it could be drawing significant current and any poor connection can cause the connectors to pit and burn. I've seen people melt cheap fuse holders from the heat generated by weak crimps to the wires.

Same thing applies to any connectors for the relay. If the wires aren't soldered to the connector you need to make good crimps.

Steve

 

[DSMunknown]

If the wires aren't soldered to the connector you need to make good crimps.

And this is why it is highly recommended that you solder every connection.

 

[Captain D]

The pump is a Walbro 255HP. It's the reason I did the AFPR mod. The original ground and trigger connectors were loose on the relay but still connected up. I didn't know it made such a difference. Thanks for the tip on soldering.