How did you reprime the pump & injectors? I just replaced my tank, sending unit, lift pump & filter. It started right up, then quit, it was not running when I parked it. Thanks for your help up front.

 

Well, you can disconnect the fuel line where it enters the box filter. I believe this is the line on the lower right of the box filter but that depends on where your box filter is mounted. You can pull the box filter and look on the back and it will tell you which port is the input. Pulling the line here allows the lifter pump to pump freely. Crank the motor until fuel spurts from this line, and you know you have prime at the lifter pump.

If for some reason you don't get fuel from the lifter pump, perhaps it is dry or airlocked. You can try pouring some fuel down the line into the lifter pump.

Then there's a air release valve after the box filter. Open than up, and crank the motor until fuel spurts here. Now you know you have good fuel to the box filter.

To check for fuel to the injector pump, you can take the top cover off the injector pump. This lets you look into the top of the pump body and see fuel pumping into the injector pump. This confirms you have good fuel to the injector pump.

And then... crack a few injectors. I use a slotted box wrench. Crack an injector nut enough that the injector line can wiggle free from the injector. Now crank the motor until you have fuel spurting out the injector lines.

The problem with air in the injector lines is that air is squishy. This means the injector pump can compress the air line a spring... but that air then never builds up enough pressure to cause the injectors themselves to open, so the air never leaves the injector line. You can crank all day long and you will just be compressing and releasing the trapped air like a spring. To release the air you must crack the injectors, and then the air has a place to escape to.

TWO WORDS OF CAUTION HERE. One, never crank more than a few seconds at a time, and always let the start cool down between cranks. I burned out a starter last year by over cranking.

Two, the injector pump works at enormous pressures. Be cautious around cracked injector lines. I've heard rumors that a fast pressurized jet of diesel fuel could damage an unprotected eyeball.

I had to crank FOREVER to finally get the air out of the line. I kept my batteries on a battery charge. I would crank, cool down, crank, cool down, for five minutes, until my batteries were drained, and then leave for six hours until they charged again, and repeat the process. This took for days and days of cranking before my motor FINALLY coughed and caught.

Now it will start on the first try every time.

 

Thank you, I don't know what the FI pump looks like, I know it is located on the front of engine but not sure just where. It is a 1996 Chevy silverado 2500 turbo extended cab. could you help with location?

 

Well, it's usually called the IP (injector pump). You can find it by following the hard metal fuel lines that come out of each injector. The injectors are the things that look kinda like spark plugs on a diesel. Those fuel lines all head back to the injector pump.

On my Chevy it's on the top front of the motor between the front arms of the intake manifold. Its smallish in size. It will have the eight injector lines running to it, as well as a couple of electrical lines (shut-off solenoid and cold start solenoid wires).

Oh yeah... if you are having trouble getting fuel to the injectors, make sure to check that shut-off solenoid. It should be getting 12v of power, and should click when power is applied.

 

Thank you!

 

I have a 1995 chevy one ton with a 6.5 diesel. I was driving to work one day and it started to really cut out, like it couldn't get enough fuel. I took it to my mechanic and he checked it out and determined the IP was bad. I bought a rebuilt IP and installed it and now I am not getting fuel to the injectors. I get fuel to the pump but when I disconnect an injector line no fuel comes out. Thanks in advance for any help you can give me.

 

Try wiring lift pump direct, you may need the extra pressure to "Burp" it, and Crack 2 or 3 injector lines. The lift pump doesn't engage until there is oil pressure built up so even though there is fuel flowing up it may not be enough to overcome air in the system. I keep a set of jumper wires and a 3/4" wrench handy just in case.
The valve up front should be to drain water from bottom of filter cartrage (bleeding while not running will kill preprime also).