barberjd

I have a 1997 12v reg cab 4x4 with 74k miles (yes, 74,000 miles). My fuel gauge read 1/4 tank but actually was empty... I ran out of gas. I put 15 gallons of diesel in tank, used the manual lift pump to prime and I am able to prime all the way to the pump. However I've pushed to no avail, as I cannot prime past the pump! Ive cracked all 6 lines to injectors and it will not push air out or bubble. I called a mechanic and he said to bump the starter and that will push the air out... No luck! Don't know what to do from here...?
Could it be lift pump, fuel pump?
Could I have picked up sediment from tank and clogged the system?


FYI, as I push on the manual lift pump a hissing noise comes from what sounds like the pump but I cannot pin point the noise.

Thanks and any advice/help is appreciated! Josh

jimduchek

The hissing you're hearing is coming from the OFV -- that's expected, and it's a good sign. Here's how you want to bleed the system:

Crack the bleeder screw on top of the fitting on the fuel filter. Pump the lift pump until diesel comes out the top not bubbly. Tighten it up.

Unscrew the line completely at the #1 injector. Crank the engine a couple seconds. Lift the line out of the injector a bit (you can't too much, with the others screwed in). You should see some wetness -- you're not going to get a big spray of diesel, if that's what you're expecting, but you'll notice a bit. If it is a bit wet, tighten it down. If not, bump the engine again.

Repeat one-by-one for all 6 injectors. By #4 the engine should start wanting to actually start, by #5 it might actually start but idle like crap. Once you've done all 6 it should purr.

patdaly

Actually, if you have the hissing of the overflow valve ( sounds like when you squeeze air thru your front teeth with your tongue ), you should have to do nothing further for it to start. In the case that it still doesn't fire ( and you are sure the solenoid is pulling the fuel lever up on the pump! ), then I do one of 2 things, I just crack the first 3 Injector lines at the injector and spin her over, when she starts, I tighten up the lines ( won't leak too much running if you don't get goofy loosening them ), or I pull the intake horn off and light her off on WD40. You have to use the WD can as the throttle control, spray as necessary, anyway, shouldn't take more than 10 seconds or so until she had them bled out.

barberjd

Thanks for the responses and detailed info! I will be off work Friday thru Sunday and will let you know the results.

1-5-3-6-2-4

Ive had them to start after cracking just #1 line. You do not have to pull the line all the way off. Actually I would recommend you don't pull it all the way off. As soon as you release the nut the seat will lift enough to purge air. Thats all you want to happen. Push air out keep fuel in.

Ideally have a second person cranking the engine. You crack and tighten the nut while they are still cranking.

barberjd

So the truck will not start... QUESTION: When I turn the key over should I hear the fuel pump in the tank?

jimduchek

On a 12v, there is no pump in the tank, it's a mechanical pump that runs off the camshaft.

jimduchek

Oh, make sure your fuel stop solenoid is working properly ad well. Its whole purpose is to prevent the engine from running, so if it's not in working order...

patdaly

As has been said, the fuel pump is mechanical, and on the side of the block ( you actually used it to prime the system ).

Now, at the back of the injection pump, there is a solenoid about 1-1/2 inches around, and 3 inches long, it has a rod pointing down, connected to a lever. Reach down and see if you can easily flip the lever up, then with someone at the key, have your fingers under the lever while they bump the key. It should snap the lever up and stay up. If it doesn't, there is your problem.

Try that and get back to us.

nascar mark

Take the start/stop solenoid (s/s) completely off inj pump to inspect properly, as I have run into 2 - s/s's over the years, that look fine and did pull up some when energized, but were so worn out that the plunger that pulls up the shaft, separated at the round clip/shaft that is connected to the plunger. Basically not pulling up enough to allow proper fuel flow.

If the s/s is working correct when energized (must bump starter and leave key to the run position) and if your lift pump is working correctly (also must be at right position on cam lobe) and your overflow valve is not weak, than you should be able to manually pump/prime your lift pump and if your not drawing any air anywhere down stream of your lift pump, your overflow valve on inj pump should start squealing after 20 or so pumps with fuel pressure.