Engine/Transmission (1994 - 1998) injection pump anti drain back valve

[st louis assembly]

The local cummins shop took care of my Hard To Start problem last week. They replaced the fuel lift pump (not enough pressure) but that didn't fix it. They found a deffective injection pump anti drain back valve and replaced it. problem solved!!!!



Where the heck is the pump anti drain back valve located? Nothing mentioned of one in the service manual and can't see where the work might have been done.

 

[DOWG]

They are probably speaking of the overflow valve which is located on the top, left hand side of the injector pump by the head.

 

[Vaughn MacKenzie]

Yep there is a banjo bolt there with a hard fuel line coming from it, that's what they replaced. Usually around $50 for the part.



Vaughn

 

[C. Harlan]

if it is the banjo bolt with the spring in there to regulate fuel pressure, I just had to buy one at work for like $89 from Cummins. Glad I didnt have to buy it! It is on the back side of the pump, and relatively easy to get to. After I replaced that, I was building boost, and built too much, and POP! There went the TC in the allison! Oops!



-Chris-

 

[Got Smoke?]

Can a faulty overflow valve really cause this much trouble? I'm having fuel delivery issues with my truck. 215 pump with PDR 370's and a custom plate and I cannot break 950* PRE-(stock)turbo, and I have no smoke except on takeoff.



I have an extra OF valve lying around, its OEM... what do I do take it apart check to make sure the spring is . 500" and swap it? Seems like that's what I heard in the past.



bought a brass threaded piece to screw into a OF valve, gonna make a homemade fuel pressure gauge..... thinking my lift pump might be shot.

 

[RBratby]

got smoke before i changed my overflow valve my truck would idle like a gasser with a huge cam in it. i changed the overflow valve and the problem is gone. the truck would not break 1000* with the bombs i have. since the change i can go 1300*+ on my pyro.

 

[Andy Redmond]

Mark:



A better way is to remove the inlet supply bolt at the back of the injection pump and drill and tap for your pressure guage's adapter.



Cleanliness is godliness here ok? No chips in you P-pump or you'll shed tears, I promise.



Have fun

Andy

 

[C. Harlan]

to check the pop off pressure of the spring, just blow into it, and if air goes through, it is bad. you should not be able to blow into the end of the banjo bolt and have air flow through.



-Chris-

 

[GRhoades]

would this overflow value cause my truck to stall when it is cold? When i 1st start it in the morning it will some times stall and when i restart it it will run rough for a little bit and then it is fine the rest of the day. I have replaced both fuel lines from the motor to the tank and the fuel filter. The fuel heater is working fine. It seems like the longer it sets and the colder it is the worst it is. Thanks for any help.