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Discussion Starter · #1 ·
So i have recently got my 4bt started and running it started very easily the very first time i started it and then i let it sit and went to turn it on again and it wouldnt fire i have to bleed the injection pump and injectors everytime i go to start it. I have checked all my fuel lines and their is no leak anywhere the only thing i havnt checked is teh helper pump when i go to pump it it has pressure when you push it way down low but not in the middle is that normal. My only guess is that their is a hole in the diaphram what else could it be is their a special way to bleed all the air out of the lines? Thanks again for all the responses.

:beer: HALFBREED:beer:
 

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You don't necessarily have to see a fuel leak for it to be sucking air. Make sure all your coppers are good at the pump and injectors. Also it can suck air at the filter. Like you think, the liftpump diaphram can do it also.
 

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You might install a short section of clear vinyl fuel line right before lift pump, to see if there's air bubbles.

In some installs the ignition switch can't carry enough current to crank the hefty diesel starter AND keep the fuel solenoid open. That's how mine is, lousy switch. Tried 2 or 3 different switches, same deal. I installed a 50 amp pushbutton for the starter and the problem you described instantly disappeared. A friend had the same problem with ignition switch, same symptoms.

Try a remote starter switch connected to starter terminals, with key switch only holding fuel solenoid open. If it starts then you'll know what to do. Cole Hersey makes extra heavy duty switches, available at all NAPA and many other parts stores.

Very confusing, cause it acts for all the world like a fuel problem, not an electrical problem. Plus when you turn on ignition switch you can hear fuel solenoid click, so that can't be it. WRONG, it can be it!
 

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Discussion Starter · #4 ·
You might install a short section of clear vinyl fuel line right before lift pump, to see if there's air bubbles.

In some installs the ignition switch can't carry enough current to crank the hefty diesel starter AND keep the fuel solenoid open. That's how mine is, lousy switch. Tried 2 or 3 different switches, same deal. I installed a 50 amp pushbutton for the starter and the problem you described instantly disappeared. A friend had the same problem with ignition switch, same symptoms.

Try a remote starter switch connected to starter terminals, with key switch only holding fuel solenoid open. If it starts then you'll know what to do. Cole Hersey makes extra heavy duty switches, available at all NAPA and many other parts stores.

Very confusing, cause it acts for all the world like a fuel problem, not an electrical problem. Plus when you turn on ignition switch you can hear fuel solenoid click, so that can't be it. WRONG, it can be it!


JimmieD I think you hit the nail on the head with that I fired her up today and she ran great i still think that there is air in the lines though i am working on rewiring the solenoid though thanks again for the great response
 

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If that's it I'm glad you found it so quickly: took me about 3-4 weeks of 100% frustration. Everything SEEMED right.....
 

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The symptoms JimmieD describes can be due to the fuel solenoid 12V connection being interrupted during starter crank. This is very easy to test, just put a volt meter on the lead to the fuel solenoid and watch it when you crank. If it maintains 12V during starter crank then it may be the amp draw problem JimmieD describes. Either way, a jumper that gets success points to something going on there.

I had a vehicle that had a sticky ign start switch so I added on a seperate crank switch. It gave me fits trying to find a lead that stayed live once the starter was engaged. I didn't think I'd have a hard time finding an uninterrupted source of 12V but I did. I felt foolish about it at the time. This was on a gasser point setup and the 12V during crank but ~6V during run ignition lead system using the ballast resistor was in place so that may have been what foiled me. Anyway, seperately wired hot through the aux starter switch and all was well.

Ken
 
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