All,
Howdy, I'm new to this site, and it looks like theres quite a few good hands here. I was wondering if anyone knows what the spec length for a 1996 dodge 5.7 Cummins overflow valve spring. Having some starting problems, and just curious if I can go ahead and check this off my list. Mine currently measures .440"
Any Ideas???
Thanks,
Thomas

 

If I remember right it should be .550 but unless you have fuel pressure gauge you are just guessing at the results of streching it. Too high of pressure will cause as many problems as too low.
Better to just buy a new one from Marty.

Precision Diesel Injection and Turbo Inc.
Marty Tompkins
toll free 888-734-7349
$22 + $5 shipping and handling.
Does over the phone with a credit card.

 

Just go ahead and put in a new one. Do like Infidel said. I don't know where you are, but Cummins here wanted $84 for one.
Tom
BTW, Welcome to the site!!

 

Thanks for the info, I agree about what you said in your reply. I would have checked it today after I did the field modification to my fuel level sending unit, but it looks almost like you have cummins tooling to check fuel pressure at the overflow valve. The more I think about it however, it seems to me like its losing its prime, and all the fuel lines appear to be ok. Do you guys know where the check valve is, thats supposed to keep fuel up by the pump. Greatly Appreciated
Thomas
P.S.
I live in Arizona

 

The check valve is in the lift pump, it does go out but unfortunately you have to replace the entire pump.

Your hard starting could also be caused by a leaking fuel return hose, they can suck air without leaking fuel. This is by far the most common cause of hard starting.

The way I check fuel pressure is to drill and tap an 1/8'' port in the top of the injection pump inlet banjo bolt and install a $4 needle valve. Easy 10 minute job.
See brass valve below.

 

Thanks for all the info fellas, I like your idea for the test fitting
Regards