Engine/Transmission (1998.5 - 2002) At what pressure do you get

[hammersley]

starting problems? I just put a higher spring in my new FASS and now at 22 PSI from 15 and a hard start when left a few minutes... ... . thoughts?????We just replaced the old FASS pump with the new Brushless One..... great exchange from the factory.....

 

[wcoomes]

22 psi??? Oh I hope your injector pump isn't damaged, according to a guy who just replaced my lift pump, the injector pump can only take 15 psi. Jim Jessup of Diesel Tune Up worked at Cummins for 33 years and retired 6 years ago. He knows these engines better than anyone I have read or talked to.

 

[RGutierrez]

My FASS is supplying 21 psi all the time with no starting problems. A 15 pound spring is on order just in case.

 

[keimmmo]

It seems like some of the pumps stand way over the 13. 5 psi ideal pressure without a problem while others give problems with only a little extra pressure. Who knows why... I had a hard start problem on my truck when warm from too much fuel pressure. I fixed the problem by reducing the pressure to a more normal level. The injection pump ran another 60k miles before it died. Get the pressure down to where it should be and you will probably be fine.



Steve Keim

 

[LowFly]

Why do you think you need 20 PSI for your VP-44 might i ask? You will not gain anything. Seveal have proved that with dyno testing. I would go back to the stock 15 PSI PS-1002 spring that was in the kit... . that is all you will ever need in my opinion... ... .



ALSO... . do a search for "FASS Hard starts". I have covered this one several times... ...

 

[jdooner]

Aw Jeez... . I just installed the BD pusher on my 98. 5. It raised my fp from 15 psi to 27psi. Am I in trouble? Is there a pressure regulator available for our trucks? Any info will be appreciated!

Thanks in advance,

Dooner

 

[JBlock]

There a flash that relief the pressure during starting.

 

[LowFly]

Aw Jeez... . I just installed the BD pusher on my 98. 5. It raised my fp from 15 psi to 27psi. Am I in trouble? Is there a pressure regulator available for our trucks? Any info will be appreciated!

Thanks in advance,

Dooner

Some say you are OK and some say NO! This is a batted around topic that never ever gets a direct answer. People have run 50+ PSI to the VP-44 (WHY... i dont know) without hurting it. The only number i have seen over and over, that i would put any faith in is Blue Chips (They are a Bosch Rebuilder) . Chips says 25 PSI Max... ... I (Me personaly) say you don't "need" any more than 15 PSI for a VP... . but you can run higher if you want to..... but won't see me over 25, you can bet on that... ...

There a flash that relief the pressure during starting.

I have heard this too... ... . The Smarty uses this from what i hear when it does its thing... . BUT i have found zero info on this in the form of a TSB number from Dodge... . if anyone knows it..... post it here... . i would LOVE to know it for my records... ...

 

[rweis]

I think Brett from II mentioned that the Bosch test stand standard is 13. 5 + - APPROXIMATELY 3. There is a diaphram that in the earlier days was prone to fail by cracking or failing seals around the edges is too much or too little pressure. I think Bosch has been putting in a stronger diaphram in the newer rebuild kits.



For me, 13. 5 +- as little variance as possible. The bypass valve that comes with the RASP is somewhat settable bypassing everything over xx back to the tank. I know you do not do a RASP, but I would bet that you could order a bypass valve from a RASP vendor. It is VERY well made and large flow ports and easy to take apart and adjust.



Bob Weis

 

[hammersley]

I put the old spring back in.....

ended my starting issue - only had it 2x - and dropped pressure to 14. 5