Engine/Transmission (1998.5 - 2002) New Lift pump pressure numbers?

[JCyrbok]

Was at the stealer the other day getting a new oil plug and was talking to one of the service guys while I was getting rung up by the cashier.



I asked him about the current fuel pressure numbers for my truck and advised him that I felt the the lift pump was becoming weak. I told him that I can easily pull my pressure down to 5psi at WOT(no Bombs), after the truck is warm. I asked him if that would consitute a weak pump, as I thought that the current number was 8psi.



He advised that they had just replaced one the day before in a 2001 CTD and advised that after talking to the Cummins techs they advised that 5psi was "fine". I think he said that 5 was the new number given to him by CUmmins. He said that it would not qualify for replacement under warranty as it was still in spec ( but would be glad to replace if I payed). I explained my whole rationale of " replace a $150 part now or a $150 and a $1300 part later, when the lift and VP go out" but it was deer in headlights time. This was not my regular Stealership so I dont know if he was blow smoke up my "tailpipe" or just didnt want alot of work going into the holidays.



A couple of questions for the membership:

1) Has anyone heard the new number before?

2) How could I get ahold of the current specs for pressure?Can I call, write or e-mail someone that would know that? Who and where?

3) How would I get ahold of the Cummins Tech guys to ask?



Any help would be appreciated. Would like the pump replaced under warranty as I really dont want to do it myself on the side of the highway during a Michigan winter ( I like many, carry a spare pump).



I do also again that some pressure is better than none, but who knows when "none" will pop up! Sorry for the long post.



Happy holidays

J-

 

[pcarlson]

J-,



I read somewhere that Cummins will go to about 3psi as long as it flows . 75 gal/min. They are more concerned with flow rate than psi according to the Cummins article. This did come from Cummins and when I find it I'll post it.

 

[JCyrbok]

Flow rate

Is there a way then to measure flow rate? I assume there is but it seems, at least to me, that it would be pretty hard to do? Fluid mechanics is not my strong point



Thanks

J-

 

[rweis]

Flow rate, could you have two containeers. start in container #1, bump key, after 20 seconds move hose to container #2. Measure container #1 *3 = flow per minute



There is also a flow rate meter I think in Northern or Summit catalog, but about $225 or so.



You could also flow rate the transmission with the meter.

 

[krs]

Do any of the DC techs who were consulted ever mention that two tests of liftpump output pressure are called for - one test running and one test not running?



The service manual (at least the one for 2001) specifies a minimum of 5-7 psi with the engine prevented from starting by removal of the fuel injection pump relay in PDC, AND a second test with the engine running at idle speed which results on a minimum of 10 psi.



I'm reading this from 14-81 & 82 (chapter 14, Fuel Delivery - Diesel) in 2001 Service Manual Ram Truck 1500-3500.



Seems to me that assurances that everything is OK so long as there is 5 psi under any condition are deceptive at the worst or plainly ignorant at best. Though I hope to never leave my truck at any dealership if I do I'd insist on a liftpump replacement if a running reading of less than 10 psi is found and will show them their own manual which calls for just that repair.

 

[RobbyRam]

You can buy or borrow a Cummins Quick Check II and a Palm Pilot or Laptop to check your fuel flow rate in Gals/hour.

Bob in Sacto.