No power at the fuel tank

hummin cummins

hummin cummins

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Dec 17, 2006
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I had an issue with my truck sitting in traffic and just dieing. It had no codes so I replaced the factory lift pump with an Air Dog. The pump wouldn't come on with the key and wouldn't run when the truck was running unless jumping across the relay. I installed a new wiring harness and still the same issue. I obviously have no power at the tank to signal the pump to run and that's where the AD picks up it's signal to turn it on. So can I pick up power anywhere else to run the pump. I know I can run key on power to it, but I prefer it to turn off if the key is on accessory. Does anyone know which pin it is at the ecm so I can see if I have a broken wire or a bad ecm. Thanks
 
You're thinking backwards.

Nothing in the tank tells the relay to kick the pump on, it's all reliant on what a pressure sensor on the engine tells the ecm and the ecm's response to turn on a relay that feeds power to the pump.

Your problem very easily could be a faulty fuel pressure sensor, which is where a higher end scan tool like a Solus, or better, is nice

Mark.
 
Thanks Mark, I'll grab a solus from my brother today. Do you know where is the pressure sensor located?
On a side note, I love the truck in your avatar. I want one.
 
Not 100% sure on the pressure sensor's location, I think the rail sensor plays into this somehow.

I like the truck in my avatar, too! I hope to build it one day. :D
The raw materials are sitting in my yard. :cool:

Mark.
 
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