Lift pump on 03's

[Rockcrawler]

I suspect this would've been beat to death but did not see in the TDR mags or in this forum. With the HPCR system, do we have lift pumps? I pulled the electric FP gage of my 01 before trading it in and will install it on the new truck if there is something to monitor.



foregive me if it was there to be found and i missed it.

 

[jwilliams3]

Yes the 03 has a fuel transfer pump located on the fuel filter housing.

You can run a banjo with schrader valve aft of the fuel filter to monitor fuel supply pressures.



--Justin

 

[Rockcrawler]

So is the pump the same as the latest pump on the gen 2's (Needs to be monitored) or is it something alleged to be better/different? I guess I'll have to look and see if there is a shrader valve there now- maybe i can use the new 18" hose Geno's offers?

 

[Fireman]

"They" say that the fue pressure isn't critical, but the volume is. This was reported a while back in this forum. I can't remember the details. Try a search.

Fireman

 

[jwilliams3]

The pump is of a different design on the 03's.

I dont know if it has the same characteristics of the Carter lift pumps.



--Justin

 

[RSnaith]

Originally posted by Rockcrawler

I suspect this would've been beat to death but did not see in the TDR mags or in this forum. With the HPCR system, do we have lift pumps? I pulled the electric FP gage of my 01 before trading it in and will install it on the new truck if there is something to monitor.

I would put that fuel pressure gauge on the truck. As was mentioned, Bosch tells us the CP3 is not as susceptible to fuel flow issues like the VP44 was, but its still important to monitor. My 03's lift pump has reduced pressure by 1. 5 PSI at idle since the truck was new, and I'm currently only running an Edge box.



If you dig around, you'll find that Dodge no longer measures pressure when testing lift pumps. They now measure fuel flow (I can't remember how much flow we need with a stock truck). Since a flow meter is a little beyond what most people want to spend, a pressure gauge is the next best option, as pressure and flow are related in a system such as ours. Not enough pressure = not enough flow. I'm not sure how much pressure we need to ensure an adequate flow, but I've been pulling my pressure down to 0 regularly with the Edge box on the truck. We plan on mounting a flow gauge on the truck when the temperatures climb above the freakin' cold mark



Rod

 

[Mopar_Mudder]

I also have been wondering about this because I am going to get an X-Monitor and don't know if I should drop the extra cash for one with fuel pressure?



Rod if you say you are droping down to 0 with the edge EZ then I guess what good is the guage going to do us? I plan on putting on the Edge Comp when it comes out.

 

[RSnaith]

Originally posted by Mopar_Mudder

Rod if you say you are droping down to 0 with the edge EZ then I guess what good is the guage going to do us? I plan on putting on the Edge Comp when it comes out.

Thats a good question. We need to correlate what pressures = what flow rate before we can honestly say if 0 pressure is ok. At 0 PSI, maybe I'm doing damage to the injection pump. Or maybe there won't be a correlation that we can count on, in which case we'll need to switch to flow meters to ensure that we're looking after the CP3 properly. I would say that in the meantime though, a fuel pressure gauge is definitely something I would be mounting, if only to monitor the health of the lift pump. If you start off at 9. 5 PSI at idle and then 6 months later your idle pressure is down to 4 PSI, I'd say the effectiveness of your lift pump has been cut roughly in half and there is a good chance that its not flowing enough volume.



Rod

 

[Mopar_Mudder]

Thanks for the comments, just trying to justify the extra $150 or so it cost to get the X-Monitor with fuel pressure monitoring. I most likely will since I don't have an Auto transmission to worry about the temp in (they drop the transmission temp when you get the fuel pressure)

 

[mgonske]

I've also been able to pull down to 0 psig with the EZ (haven't checked with it disconnected).



While my truck was at the dealer's service department last week (on an, I hope, unrelated issue--See this thread), they performed the flow rate test by just running the pump into a bucket. They told star they ran it for one minute, and was told they only need to run it for 10 seconds, and get at least a pint in the bucket. On the 10 second run, they got more like a quart. So anyway, there's further evidence of the flow rate rather than pressure test criteria.

 

[RSnaith]

Originally posted by mgonske

they performed the flow rate test by just running the pump into a bucket. They told star they ran it for one minute, and was told they only need to run it for 10 seconds, and get at least a pint in the bucket.

That would definitely be a poor mans test but functional I would be concerned that the lift pump wasn't working off-idle though. We've seen several lifts (on 02's and down) that looked like they were working well at idle, but when you brought the truck under a load, they dropped badly.



And there is another issue with the factory flow test. The factory minimum flow is based on stock HP. As the power keeps going up on these trucks, we'll need more and more flow to keep the CP3 healthy. Right now, DD3s and an Edge box appear to be safe, however there have been two more aggressive trucks who emptied out the low pressure side of the CP3, most likely due to not enough lift pump flow.



Rod

 

[Mopar_Mudder]

Ok I have always been of the mind that do it right the first time, spend a little extra and it will save you in the end.



So that said can you just add a high volume pump that would feed the lift pump. Something like the high volume Carter that I run on my off-road truck. How much pressure can you through at the lift pump with out doing damage. $200 for a pump and some fittings may save you lots of money in the long run.

 

[RSnaith]

I've been poking around with my Bosch contacts, trying to find out what kind of pressure/flow the CP3 can safely handle at the inlet, but haven't had much luck. There will definitely be a limit though, and I'm going to guess that 12 - 14 PSI will be it (the VP44's lift pump was about 25% smaller than its inlet pressure limit). I'll be replacing the stock lift pump in a month with a 14 PSI unit and seeing what happens.



Rod