Power to the fuel pump...
Thread Starter
TECH Apprentice
Joined: May 2006
Posts: 308
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From: Nebraska
Power to the fuel pump... Guys,
I installed a new Walbro 255 fuel pump, everything is connected back together (black to black, red to gray, etc...) just fine...all connectors and grounds are fine....Fuel pump relay is brand new, and the fuse is fine too. For some reason now though, there's no power reaching the pump... I probed the PRIME in the electrical center and it didn't light when I turned ignition on...which tells me the circuit between the electrical center/pcm and harness must be bad for some reason.....this is strange....everything worked fine before I replaced the pump. What should I do now?....ALLData suggest testing the control signal....where is that?....Do I need to replace the PCM?...anyone else have the same problem one time or another?......
Stroker2112
I installed a new Walbro 255 fuel pump, everything is connected back together (black to black, red to gray, etc...) just fine...all connectors and grounds are fine....Fuel pump relay is brand new, and the fuse is fine too. For some reason now though, there's no power reaching the pump... I probed the PRIME in the electrical center and it didn't light when I turned ignition on...which tells me the circuit between the electrical center/pcm and harness must be bad for some reason.....this is strange....everything worked fine before I replaced the pump. What should I do now?....ALLData suggest testing the control signal....where is that?....Do I need to replace the PCM?...anyone else have the same problem one time or another?......
Stroker2112
I'm experiencing something similiar to this as well. I just installed a Magnafuel 4303 pump and Nasty Tank. The pump relays aren't working when using the stock fuel pump supply wire (gray) to trigger the Magnafuel pump relays. When the key is turned on, the pump will run for 1-2 seconds, then stop. I've verified the relays and fuses, but no power is going to the gray wire for the pump. Rewired the Magnafuel pump relays using a switch 12v source from the front of the car and the pump works fine.
My fuel gauge is also not working. The fuel level sending unit with the Nasty Tank is wire into the purple and black/white wire on the stock harness. I've got 8 gallons in the tank and the gauge is buried on E.
My fuel gauge is also not working. The fuel level sending unit with the Nasty Tank is wire into the purple and black/white wire on the stock harness. I've got 8 gallons in the tank and the gauge is buried on E.
Last edited by ozws6; Jan 7, 2007 at 04:43 PM.
Thread Starter
TECH Apprentice
Joined: May 2006
Posts: 308
Likes: 0
From: Nebraska
ozws6,
I found the cause of my problems to be an overlooked blown fuse. Check that right away....it could be a simple fix for you. I looked over it initially (ecm, 20amp fuse ) when I tested the relay, circuits, etc. Interesting enough, my problems continued after I found the culprit, I replaced the fuse and got everything working great. Then I filled the tank completely up for a dyno session, and all of a sudden I had no fuel pressure. I have power to the pump, and everything else is fine except the fuel pressure at the rail. My guess is that the hi-pressure pump hose came off the sending unit. So tonight I'll be siphoning 25 gallons in order to get back into the tank to fix it....don't really know what else it could be. I can also tell you that GM issued an advisory on the metro 150 (4 square) connector, might want to look at yours for integrity purposes. Good luck.
I found the cause of my problems to be an overlooked blown fuse. Check that right away....it could be a simple fix for you. I looked over it initially (ecm, 20amp fuse ) when I tested the relay, circuits, etc. Interesting enough, my problems continued after I found the culprit, I replaced the fuse and got everything working great. Then I filled the tank completely up for a dyno session, and all of a sudden I had no fuel pressure. I have power to the pump, and everything else is fine except the fuel pressure at the rail. My guess is that the hi-pressure pump hose came off the sending unit. So tonight I'll be siphoning 25 gallons in order to get back into the tank to fix it....don't really know what else it could be. I can also tell you that GM issued an advisory on the metro 150 (4 square) connector, might want to look at yours for integrity purposes. Good luck.
Thread Starter
TECH Apprentice
Joined: May 2006
Posts: 308
Likes: 0
From: Nebraska
The hi-pressure hose disconnected (underneath the metric 150 connector area on top) all by itself. So I put a new length of hose (longer) in and a much tighter clamp....everything is running fine now. Now I just need to "dial" everything in at the Tuner/dyno.....
Stroker2112
Stroker2112
