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Gm Tech (Cam)
Gm Tech (Cam), GMC Mechanic
Category: GMC
Satisfied Customers: 29428
Experience:  GM Grand Master Technician 2007. 14 year experience.
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My 2007 gmc diesel ran out of fuel. I put 4 gal in. I primed

Customer Question

My 2007 gmc diesel ran out of fuel. I put 4 gal in. I primed it with the pump and the electric pump and it starts for about three seconds and then dies.
Submitted: 1 year ago.
Category: GMC
Expert:  Gm Tech (Cam) replied 1 year ago.

Hi there, I am Cam. I am sorry to hear about this issue, it’s a bit of a pain but I will help you out.

The electric pump you hear is not for the fuel pump, this engine does not use an electric lift pump. IT has only the mechanical lift pump mounted on the back if the injector pump. So the only way to prime it after running out of fuel is to open the bleeder on the top of the fuel filter housing, then pump until fuel comes out. This can take 60-100 pumps. Then after it gets fuel, close the bleeder and continue pumping until it gets stiff. This will take many pumps. You can have someone crank the engine while you pump during the second portion of the bleeding/priming sequence until it runs. This will get you going. Once fuel does come out of the bleeder you should notice a different feel in the plunger. IF not then its possible the primer pump is failing. I have replaced the fuel filter head for issues with priming.

Please try this and let me know what you find.

Customer: replied 1 year ago.
I opened the screw and pumped until fuel ran out, closed it and pumped until it was stiff. Still ran for three seconds and stopped. Got someone to crank after I repeated while I kept pumping. Still did same thing.
Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 1 year ago.
The call would be easier, but if it's more convenient for you continue with texting.
Expert:  Gm Tech (Cam) replied 1 year ago.

Sorry for the delay. I was on a road test.

IS yours a dual tank setup?

Customer: replied 1 year ago.
No
Customer: replied 1 year ago.
I already paid with paypal. Let's just continue like this.
Expert:  Gm Tech (Cam) replied 1 year ago.

OK, sounds good. IF you keep pumping with the bleeder closed, does fuel come out anywhere?

Customer: replied 1 year ago.
Can't see any
Expert:  Gm Tech (Cam) replied 1 year ago.

Does it keep running if you keep pumping the plunger?

Customer: replied 1 year ago.
I can see fuel under pressure if I move the bleeder screw. It didn't keep running the two tomes I tried pumping while it was being cranked
Expert:  Gm Tech (Cam) replied 1 year ago.

But it starts and stops, is there any question about the type of fuel put in? Was it by chance Gas or really old fuel that may be contaminated?

Customer: replied 1 year ago.
I just went to the station for the diesel.
Expert:  Gm Tech (Cam) replied 1 year ago.

OK, This is strange, usually the pumping/priming makes it run. IS there any warnings on the dash?

Customer: replied 1 year ago.
low fuel. Battery. It is hooked to a charger. Engine check. And something that looks like a spring comes on And goes off
Expert:  Gm Tech (Cam) replied 1 year ago.

the spring is a glow plug indicator. At this moment after everything, does it still just start and stall?

Customer: replied 1 year ago.
It starts and I guess it stalls. It quits like it runs out of fuel.
Expert:  Gm Tech (Cam) replied 1 year ago.

OK, we need to try a bit more fuel then. You might be lower than you thought. IF this does not change it then we might be looking at something deeper like a pump, but that’s a major issue, and with only running out of fuel, it usually does not end up like that.

Customer: replied 1 year ago.
I just pumped it up and cranked it, after it started I immediately pumped the pedal and it roared and quit. The pump gets stiff, there's still about a quarter slack that you can push down before reaching the stiff part.
Expert:  Gm Tech (Cam) replied 1 year ago.

Ok, and pump after it gets stiff several times to see if that changes anything.

Customer: replied 1 year ago.
While waiting I did the shallow pumps 80 times and it still died. Seems like pumping the pedal doesn't add fuel. When I make it roar it dies quicker than just cranking it with my foot off the pedal. It runs just as long even if I don't pump under the hood.
Customer: replied 1 year ago.
Was this a coincidence that it started after running out of fuel?
Customer: replied 1 year ago.
That the problem started
Expert:  Gm Tech (Cam) replied 1 year ago.

It my have been. The fact it does not remain running and you cannot make it stay running with the primer suggest it may be an injection pump issue, is there a chance you can measure the vacuum on the system at the test port?

Customer: replied 1 year ago.
I don't have a gauge. Where is the test port
Expert:  Gm Tech (Cam) replied 1 year ago.

There is a black test cap with a port under it that measures the vacuum between the pump and filter. WE need to see what the vacuum that the injection pump is pulling.

Expert:  Gm Tech (Cam) replied 1 year ago.

Perhaps I should ask when you last changed the fuel filter?

Customer: replied 1 year ago.
I just had someone come to the house and change it with no changes.
Expert:  Gm Tech (Cam) replied 1 year ago.

OK, can we try a bit more fuel just in the off chance?

/Otherwise we need to get it scanned and see what the computer is seeing.

Customer: replied 1 year ago.
I'll get more fuel tomorrow and let you know the result.
Expert:  Gm Tech (Cam) replied 1 year ago.

Ok, I really hope that’s it. IT strange that it did not run by now.

Customer: replied 1 year ago.
I put in another 5 gallons of fuel. Still only starts for 3 seconds at a time. Guess I'll have it towed 30 miles to the nearest Chevy dealer Monday
Expert:  Gm Tech (Cam) replied 1 year ago.

It makes no sense unless the lack of fuel finished off the pump. These were bad for the injection pump ceramic ball inside failing.

Customer: replied 1 year ago.
I hope it's simpler than that.
Expert:  Gm Tech (Cam) replied 1 year ago.

So do I. To be honest I am hoping its just an issue with how you primed it but it does not sound like it is. .

Customer: replied 1 year ago.
I'll let you know.
Expert:  Gm Tech (Cam) replied 1 year ago.

Thanks.

Customer: replied 1 year ago.
The problem was an electrical one. A mouse got under the under hood fuse box and chewed a wire.
Expert:  Gm Tech (Cam) replied 1 year ago.

Odd the timing of it. Glad you got it sorted out. Put some moth balls under there to keep them out.