Lift pump questions

[Kevin 007]

Working on a 94 1 ton minibus with what looks to be a 6.2 in it. I thought 94 was the first year of the 6.5, all the valve cover labels have been painted over so there is no indentification that stands out at me. It is a non-turbo, looks just like a 6.2, all mechanical fuel inj and so on.

There is a bad fuel leak around the lift pump. cant really tell if its the rubber fuel lines or the pump that is ******* fuel. So I am going to order a new lift pump and does anyone know off hand what size the rubber fuel lines are?

Any tips to installing a 6.2 lift pump. Other than making sure the lobe on the crank is in the high position.

 

[lotzagoodstuff]

Don't know the size off hand, but if you measure the nipples on the fuel pump with a caliper beyond the beaded/bumped section near the end, it should tell you exactly what size id hose you'll need. The hose should say what size it is on the layline, but if it's old and dirty, that information is probably long gone. Good luck to you.

 

[lindstromjd]

Pretty sure 93 was the first year of the 6.5, but they kept the 6.2 around for a few years, too.

Lift pump is easy to install; just like you said with making sure the cam lobe is in the right position. Those things suck to have to move by hand.

 

[Kevin 007]

Turns out it is in fact a 6.5

 

[Kevin 007]

Well I made a giant mess!
Lift pump was spewing fuel out of the center seam (its toast) and I went to remove it and rounded off the nut.
So I left it and installed an inline electric pump in the same area. Ran the supply line from tank to the pump and ran a new line up to the factory fuel filter in the back of the valley pan mounted on the intake manifold. Its getting fuel to the filter and to the IP.

Can't get the thing to start

I had the 6 rear most injector lines open and cranked and cranked and got little fuel if any on a few of them. Is there a trick to bleeding these things?
The filter canister almost looks as if its upside down to me. The drain screw is on the top. So I just opened it and fired up the electric pump till all air was out of it.

Im thinking maybe the Fuel shutoff solenoid is toast? which electrical spade on the pump is the shutoff? I just want to hotwire it and see what happens. I even sprayed a "little" WD-40 down the throat and it didn't react to this at all, not even a burp. There seems to be great flow out of the electric pump. Is there and ECU or something that could be not working?

 

[lindstromjd]

There's a couple reasons a 6.5 won't start. Depends on if it's an ECU engine or a mechanical engine. You're certain you are getting fuel to the IP? And the glow plugs are working?

 

[Kevin 007]

The glow plug relay is cycling as it should. Have not tested the glow plugs themselves but they worked fine before I did this work.

Everything on the engine looks mechanical. The IP doesn't look like an old D-B2 ro me though. Which spade on the pump is the fuel shutoff?

How can I check for an ECU?

 

[lindstromjd]

If everything is mechanical then you won't have an ECU. They're on later model turbo 6.5's. The spade for fuel shut off is on the left (looking at it from the front of the truck) of the IP. Close to the radiator. Red wire in the picture. If you put 12V power to it, you should hear an audible "Click" of the solenoid opening. If you don't, then the shut off solenoid is bad.

 

[Kevin 007]

Well I got er going...just took a whole lot of bleeding!! Runs well, smooth and responsive but after sitting for a while it won't fire up anymore and I end up bleeding the lines again even though they have fuel instantly...and eventually it will start again.

 

[Kevin 007]

COuld fuel be draining back through the lift pump???

 

[lindstromjd]

Yeah, I'd say that if it runs fine but won't start after you let it sit then the one-way valve inside the lift pump is bad. Even with an electric pump, you need that valve to keep fuel in the lines where it belongs. Otherwise it'll just drain back and your electric pump will end up compressing a lot of air when you turn it on.

 

[Kevin 007]

Do you know of any check valves off hand that I could purchase? And would I install it between the electric lift pump and injection pump? or between lift and tank?

 

[lindstromjd]

Do you know of any check valves off hand that I could purchase? And would I install it between the electric lift pump and injection pump? or between lift and tank?

Off hand, no, I can't think of any. But you'd install it between the lift pump and IP.

 

[Kevin 007]

Ok, thanks.

Its strange though, when I get the no start situation; I will open the bleed screw on the filter and turn the key on (electric lift pump come on) and there is fuel instantly at the bleed screw, no air!

But it insists that I bleed the injectors...sometimes several times.

 

[lindstromjd]

Ok, thanks.

Its strange though, when I get the no start situation; I will open the bleed screw on the filter and turn the key on (electric lift pump come on) and there is fuel instantly at the bleed screw, no air!

But it insists that I bleed the injectors...sometimes several times.

If that's the case, then you might have leaky injector lines. Or bad gaskets / crush washers on the injectors themselves. Also, check your return lines that connect all the injectors together and then to the return line itself.