Ok, before you say main relay...hear me out....
-91-lovefab LF800, AEM EMS
-Car has been starting/running fine up until a week or so ago when I went to move it and it wouldn't fire...would just crank.
-A year ago I replaced the main relay and ignition switch. The old ones still worked fine...just replaced them to be safe.
-I determined the fuel pump was not getting power. I couldn't hear it prime when switching the ignition on.
-The fuel pump fuse is fine, I replaced it anyways. I have checked all other fuses in the car repeatedly.
-I tried my old main relay and there is no change...I even tried re-soldering it and again...no change.
-I tried unplugging the fuel pump resistor and jumping the connection....no change.
-I then determined that the fuel pump relay(small 4 prong relay behind drivers seat was not transferring power.
-There are 4 wires: Yellow-12V switched on by ignition, Black/red-goes to fuel pump, Black/Yellow-goes to main relay, Solid Red-??? I am not sure
-If I remove the relay and place a jumper wire between the Yellow/12V wire to the Black/Red/Fuel pump wire, the fuel pump comes on when I switch on the ignition and the car will start/run just fine. The only difference is that it doesn't just prime and then shut off after a couple seconds when the car is just switched on. The pump will just keep running.
-I ordered a new fuel pump relay and installed it....no change. I can feel and hear the relay clicking on for a couple seconds when I turn the key on...and then feel/hear it again when I turn the key to start...as it should, but it isn't transferring the power.
-So, the relay is getting power, has a fine connection to the fuel pump, and seems to be getting the correct signal from the main relay to kick on and off.
Any ideas? Where does the red wire to this relay come from? Is that a ground? I can at least start/drive the car with the jumper wire in place, but it just isn't "right". There were no changes to anything between the time that is was starting fine and then all of the sudden the fuel pump wasn't getting power.
Thanks.
IMG_1623 by blodi, on Flickr
-91-lovefab LF800, AEM EMS
-Car has been starting/running fine up until a week or so ago when I went to move it and it wouldn't fire...would just crank.
-A year ago I replaced the main relay and ignition switch. The old ones still worked fine...just replaced them to be safe.
-I determined the fuel pump was not getting power. I couldn't hear it prime when switching the ignition on.
-The fuel pump fuse is fine, I replaced it anyways. I have checked all other fuses in the car repeatedly.
-I tried my old main relay and there is no change...I even tried re-soldering it and again...no change.
-I tried unplugging the fuel pump resistor and jumping the connection....no change.
-I then determined that the fuel pump relay(small 4 prong relay behind drivers seat was not transferring power.
-There are 4 wires: Yellow-12V switched on by ignition, Black/red-goes to fuel pump, Black/Yellow-goes to main relay, Solid Red-??? I am not sure
-If I remove the relay and place a jumper wire between the Yellow/12V wire to the Black/Red/Fuel pump wire, the fuel pump comes on when I switch on the ignition and the car will start/run just fine. The only difference is that it doesn't just prime and then shut off after a couple seconds when the car is just switched on. The pump will just keep running.
-I ordered a new fuel pump relay and installed it....no change. I can feel and hear the relay clicking on for a couple seconds when I turn the key on...and then feel/hear it again when I turn the key to start...as it should, but it isn't transferring the power.
-So, the relay is getting power, has a fine connection to the fuel pump, and seems to be getting the correct signal from the main relay to kick on and off.
Any ideas? Where does the red wire to this relay come from? Is that a ground? I can at least start/drive the car with the jumper wire in place, but it just isn't "right". There were no changes to anything between the time that is was starting fine and then all of the sudden the fuel pump wasn't getting power.
Thanks.
IMG_1623 by blodi, on Flickr
Last edited: