is there a check valve on the return line to the tank? i have an aftermarket fuel pump and when i bump the starter you can hear the fuel run back into the tank, it will shut off after 42 seconds.originally it was almost instant. any feedback will be helpful

 

The pump will run for aprox. 30 seconds when the starter is bumped. Depending on pressure yes bypass fuel will be returned to the tank. What is your fuel pressure.

 

When you turn the key to ON then the fuel pump is supposed to prime the system for about 2 seconds. If you bump the starter then the fuel pump will run for about 25 seconds. If your fuel pressure is over 14-16 psi then the overflow valve will let fuel flow back to the tank but its not a check valve since the overflow valve has a very small hole in it which is thought to always allow fuel to pass through the VP and back to the tank. Or another thought is that the hole is there just to release internal pressure in the VP after shutdown so the VP doesn't have to fight that pressure upon start up. Kinda like a refrigeration compressor.

 

I'm going to the garage to find out what the pressure is when I first turn on the key and when I bump it over. If I try to start after I turn on the key it just turns over and doesn't even try to start, but if I bump it and wait for the pump to stop and then try to start it, it will start after a moment. I've stories about my pump that a detent ball can be to blame, but to take it in for warranty work is something else.
what are you using for your fuel pressure gage? Is it hard lined or an electronic?

 

To save lots of typing for me, read this thread. It might be the answer to your problem. http://www.cumminsforum.com/forum/98...-starting.html

 

Encase you do not have membership at the other forum, maybe this will help...

I am having the same prob. Fires up in the morning and dies instantly... I bump the starter, and let the fuel pump run for a bit... Then I need to crank for a while, and even tap the throttle to get it fire.

I found a small leak on my fuel filter canister today, the filter canister is from an 01.

Over night the fuel drains back, cause the leak was letting in air, but not dripping fuel, until today... Then it wont start unless you prime the system first...

 

after reading all the replies, i started to do some searching and found that the return line off the back of the head, down to the "T" (which goes to the pump) and beyond is full of pinholes from rust, I've ordered a new line and it hasn't come yet, but as soon as I can replace it I'll find out if that was the problem. Thanks to all your suggestions

 

I dont know how you can expect an answer that would help you diagnose the problem when you ask this.

If you have rust holes in a fuel line you must have fuel dumping on the ground. Not running back into the tank.

 

If that line tee's into the suction line for the pump and it has holes in it then the suction from the pump will be greater than the return from the head and cause it to suck air into the pump and also allow air to enter line at shut down and drain line all the way back to tank.

Rick

 

i need to ask questions as to all possibilities as i need to relay this info to the person that is helping me as my disability won't let me work in the engine compartment, and believe it or not all the threads that were suggested to me to read was very informative, more so than some other threads