bj42 fuel issue please help

[wileycoyote]

I just bought a bj42 on a bj44 frame with a 3b engine. In order for me to start this truck i have to put an airhose in the tank and pressurize the tank to make it start. Then the truck will only run for a minute or two. If i keep the air going, the truck will run fine. Any suggestions? Thanks for the help in advance.

 

[David*BJ70]

Maybe it suck air somewhere in the hose. Try to lay under the truck and check for leak during someone push air in the tank. Otherwise, check the hand pump, fuel filter, hoses conections....

 

[wileycoyote]

Doesnt seem to be a leak anywhere. Can i just hook up a 12volt electric fuel pump in the line?

 

[lostmarbles]

Maybe it suck air somewhere in the hose. Try to lay under the truck and check for leak during someone push air in the tank. Otherwise, check the hand pump, fuel filter, hoses conections....

Good advice.

Most likely a leak in this line here (highlighted in red):


A leak here will generally not drip fuel unless you've pressurised your fuel tank. But it will allow air to be sucked in (instead of fuel) when your fuel pump tries to take fuel fromj your tank.

Another alternative is that your fuel pump isn't working ... which can happen when crud gets stuck under either of the non-return valves there.

Doesnt seem to be a leak anywhere. Can i just hook up a 12volt electric fuel pump in the line?

If you want a mickey-mouse repair. Sure!

 

[wileycoyote]

You guys are awesome. I will go into detail and check this out. Thanks

 

[lostmarbles]

You guys are awesome. I will go into detail and check this out. Thanks

There's a short section of rubber hose there that often causes problems. It's diameter is so small that it is hard for the clamps to establish a seal. Furthermore engine heat causes the hose to perish and the clamps to loosen their strangle-hold:

 

[roscoFJ73]

In addition to what Tom pointed out,the hand primers often let air in . A lot of the owners here replace them with a Bosch unit off a Mercedes diesel.You will have to ask one of them for the finer details,but they are only $20 or so on ebay.

I hope some 44 series pics are forthcoming

 

[wileycoyote]

 

[wileycoyote]

I just drove 12 hrs one way to nc to pick this beast up. Cable lockers front and rear. 44 frame with 42 body. 3b and im thinking about putting an aluminum tub on her. Its a beast i fell in love with. There will be a thread on her shortly. Literally just walked in the door.

 

[wileycoyote]

Applied pressure and i looked, pouring diesel out around fuel pump. To dark ti diagnose tonight but first light im on it.

 

[simonliew]

Hi,why would a leak at the red line make the engine no start,that is the fuel return line,unless i can't think today.
leak around injection pump,prob the fuel primer pump,buy one from a diesel shop,way cheaper than the dealer.
Simon

 

[lostmarbles]

Hi,why would a leak at the red line make the engine no start,that is the fuel return line,unless i can't think today.
leak around injection pump,prob the fuel primer pump,buy one from a diesel shop,way cheaper than the dealer.
Simon

The fuel pump sucks on that red line as well as on the line connected to the tank. So any air leaking in from that line will get pushed into the fuel filter in preference to diesel from the fuel tank. And from there the air gets pushed into the injector pump. Once in the IP, air stops the IP from delivering fuel to the injectors (because under the action of the little pistons within the IP, the air compresses and re-expands rather than moving anywhere overall). So the engine will die and won't restart till someone does something to get uncontaminated diesel back into the IP pump and injector lines.Cheers

 

[roscoFJ73]

I just drove 12 hrs one way to nc to pick this beast up. Cable lockers front and rear. 44 frame with 42 body. 3b and im thinking about putting an aluminum tub on her. Its a beast i fell in love with. There will be a thread on her shortly. Literally just walked in the door.

Cool ,cable lockers a big bonus. What is a 44 series frame ,I was expecting it to be the length of a 45

 

[roscoFJ73]

Applied pressure and i looked, pouring diesel out around fuel pump. To dark ti diagnose tonight but first light im on it.

Im wondering if the hand primer is screwed down?

 

[wileycoyote]

So pulled the two batteries out and sure enough, a little hole i couldnt see. So i tore all the rubber hoses out and replaced everyone of them. New clamps as well. This beast purrs like a kitten.

 

[roscoFJ73]

These are super reliable,its taken 30+ years for that to start leaking. If you kept that thumb clamp ,I would replace that as well.

 

[roma042987]

Just saw this thread pretty cool so one more to your collection. Glad to here you got her goin. I can finally say all my gasser cruisers are gone and won't ever look back.

 

[D0g]

There's a short section of rubber hose there that often causes problems. It's diameter is so small that it is hard for the clamps to establish a seal. Furthermore engine heat causes the hose to perish and the clamps to loosen their strangle-hold:

View attachment 627973


View attachment 627973

How do you take off the lower portion of the return hard line? I can't see where it connects on the back of the pump.