97 starts then dies, air in fuel

[Joninva]

Truck starts up good, runs about 20 seconds, then dies & won't crank right up. If I pump the hand primer, and hold throttle to floor, it will start up, acts like air in fuel. Lift pump is 1.5 yr old, same thing would happen with old LP. Only happens at initial start up, and usually only if truck sits a few days. Starts good rest of day. Don't see any fuel leaks. Truck is stock, 255,000 miles. Any suggestions? Thanks

 

[Signal73]

Check the metal elbows on top of the fuel tank sending unit, also the return lines from the back side of the injection pump all the way back to the tank. You may not see a fuel leak because it is letting air enter and draining the fuel back to the tank. I’d also look at last time you changed your fuel filter and cleaned the pre filter screen attached to the fuel heater. When you pull the power plug for the fuel heater if it’s wet with diesel that’s another leak location.

 

[GAmes]

https://www.cumminsforum.com/forum/94-98-engine/58777-joe-gs-fuel-system-writeup.html

Installing a fuel pressure gauge is a great help for diagnosis.

 

[HHhuntitall]

Also, check the return line fitting on the pump, in front, against the cylinder head... It's a spring loaded check valve that wears over time, and if it leaks, it will allow the engine to lose prime, dumping the fuel back in the tank.... I keep these in stock, and sell at least 3-4 every year. I recommend the Bosch replacement...…. they seem to last longer.

https://www.genosgarage.com/product/2-417-413-101-kit/fuel-system-accessories-replacement-parts

 

[Dl5treez]

Mine was the drain back check like HHhunitall says. Started as intermittent then got worse enough to motivate me to look into it. Replaced and been fine for 7 years now.

 

[Joninva]

Thanks for the replies. I will try the drain back valve. This started out as an intermittent problem, but now happens every time.

 

[DUtt]

banjo bolt washers on top of the fuel filter cap might be leaking

 

[GAmes]

banjo bolt washers on top of the fuel filter cap might be leaking

If they were there would be a constant flow of fuel because the filter is pressurized. It's been five months, the problem is probably fixed.

 

[DUtt]

air is thousands of times thinner than diesel fuel.. mine wasn't leaking fuel, it was sucking air thru those washer when not running causing air to get in the system overnite or after not running for a few days causing drainback to the tank..replacing then solved my hard start and engine dying problem..see ya dan

 

[Joninva]

I haven't had time to work on the truck, been too busy at work. I'm selling it to my brother in law, he just wants it before winter. So it's mostly been sitting. Thanks for the help and I'll let y'all know when I make some progress