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Old 10-12-2010, 07:48 PM   #1
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6.2 Diesel Electric Lift Pump Install

Going to replace mechanical lift pump on my 6.2 Jimmy with a electric fuel lift pump. I replaced the mechanical lift just a month a or two ago, and it appears to have stopped working, not sure why. When I replaced the old mechanical lift pump it appeared to damaged, and not working. The new seemed to work fine for a while, and then the other day I was at work and it kept stalling. I thought it was the fuel filter, or maybe that I had run the fuel tank to empty (guage does not read right, think it maybe sender in tank having the problem. When I replaced the primary fuel filter, I noticed that the filter was not all the way full. Tried the turning the engine over with the the fuel filter removed (to check the pump) no joy. Added 8 gallons of diesel and repeated, still no joy. Decided instead of going through the painstaking reinstall of another mechanical, just replace with an electric. Got a generic lift pump from NAPA, says its good for gas or diesel. I looked under the Jimmy tonight and and was looking for a good place to mount. Looking for suggestions on why mechanical lift failed, and thought about the electric and where to install. Instructions say mount in the back near fuel tank.
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Old 10-12-2010, 08:30 PM   #2
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I think you have other problems. Sounds like you might have a fuel leak of some sort. Im pretty sure if the fuel pump goes out, your injection pump will pull enough to keep it running and primed. I not 100% tho, someone else will chime in. I mounted my electric pump to the fire wall, under the fuel filter.
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Old 10-12-2010, 11:43 PM
Posted in reply to protechk5's post starting "I think you have other problems. Sounds..."
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Not exactly apples to apples, but my 100KW genset uses an electric clicker type fuel lift pump.
And that is how the autostart panel starts and stops it.
It turns on the lift pump and hits the starter and it runs.
It turns off the lift pump, and the genset stops instantly.

My Stanadyne injector pump cannot suck fuel through the stopped lift pump.

However, that does not mean yours can't through a mechanical pump.

You might want to double check to see what went wrong with the new pump. It might be something in the drive for it that needs attention.


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Old 10-13-2010, 08:56 AM
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Generally once the engine is started the IP can pull enough fuel to keep running regardless if the mechanical lift pump is working. However it more than likely will not start with a bad lift pump. You mentioned "it kept stalling" which seems like you were able to restart the engine several times. I would tend to look elsewhere for a problem because if the lift pump caused the engine to stall for some reason then I very much doubt you would be able to restart the engine.
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Old 10-13-2010, 11:05 AM
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Stalling sounds like and air leak on your fuel feed. I would look at all of the rubber lines from tank to injector pump. One that is most mist is the one under the intake going to the injector pump.
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Old 10-13-2010, 09:29 PM
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Thanks for all the tips

Thanks for all the good gouge, I plan on trying to take a look at the problem tommorrow evening in more depth. Will try to take some pics and post the results.

Question if I solve the above issue, I've heard that the electric lift pump I will no longer need to prime, since the lift pump can pump all air out of the system? Thoughts?
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Old 10-13-2010, 10:06 PM
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Its interesting update
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Old 10-14-2010, 05:24 AM
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sounds like text book air in the fuel system. Check for leaks, and all connections then thorowly bleed the fuel system all the way to the injectors.

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Old 10-14-2010, 07:23 AM
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I put a universal electric fuel pump on my 82 K2500's 6.2...I mounted it on the crossmember that the rear cab mounts are on,close as possible to the fuel tank,as electric pumps cant pull fuel from long distances without running too much and will burn them up...had mine on there 6 years,in addition to the stock mechanical pump,I have not yet had to replace a fuel filter,but I would think the electric pump will at least help purge the air out of a new one if you leave the top bleeder screw open and run the pump..my truck will run with the electric pump switched off ,on the stock mechanical pump,so I guess my electric pump does not block fuel flow with it shut off?..
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Old 10-15-2010, 09:36 PM
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Up and Running

I think I ran out of fuel was the original causal factor. I have replace the fuel guage on the dash, but I believe I need to replace or fix the sender unit in the fuel tank. After not finding a super inviting place to mount the electric fuel pump, I used my hand vacuum to pull fuel from the tank (added about 8 gallons to fuel tank before this process) at the inlet to the fuel pump. Pulled vacuum on the rubber inlet hose coming up to the primary filter. I then topped off primary fuel filter, installed and pulled vacuum off bleed valve on top of filter housing. Changed out secondary filter, topped off new filter reinstalled.


Thanks for all the help.

Up and running now, but still thinking about that lift pump.

While I was playing with the primary filter I was trying to check if the lift pump was working by, turning the engine over with the bleed valve on top of the filter open, thought I would see fuel coming out, never did. Whats a good method to determine that the lift pump is working?
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