Gen3 lift pump pressure?

[Alphacowboy]

I was wondering what you Gen3 guys get for stock pressure from the stock lift pump?



Thanks,



Matt

 

[bpenrod]

Mine was around 8 psi at idle and 6 on the highway. When I turned the boxes up I could pull it to zero at will.

 

[Alphacowboy]

that low huh? That seems super low to me!

 

[Briman]

Mine is as bpenrod says. Almost exactly. 8-9 at idle. 5 or 6 on road. Suck to zero at will.

 

[bpenrod]

I didn't like it either so I got rid of the stock lift pump. On the other hand I think that falls within spec and was working properly. Now I have 18 at 1idle and can only pull it down to 14 or 15 at WOT. I'm not sure if that is too far the other way so I'm going to put a lighter spring in it and hope for the happy middle!!

 

[WMcGuire]

I didn't like it either so I got rid of the stock lift pump. On the other hand I think that falls within spec and was working properly. Now I have 18 at 1idle and can only pull it down to 14 or 15 at WOT. I'm not sure if that is too far the other way so I'm going to put a lighter spring in it and hope for the happy middle!!

Oo. I'm not real familiar with these fuel systems but assume the pump "pushes" the fuel through the filter, where do you take the pressure readings, after the filter?

are these pressures with a new filter?

 

[bpenrod]

All of my pressure readings are after the filter(s) at the inlet side of the CP3 and were the same after doing a filter swap.

 

[rbattelle]

8-9 may seem low, but with a CP-3 it's really flow rate that counts. Factory minimum spec is 38 gph. The CP-3 has an internal gearotor pump so inlet pressure isn't so much of a concern as it was with a VP-44.



-Ryan

 

[gsbrockman]

8-9 may seem low, but with a CP-3 it's really flow rate that counts. Factory minimum spec is 38 gph. The CP-3 has an internal gearotor pump so inlet pressure isn't so much of a concern as it was with a VP-44.



-Ryan

Exactly... . after I had my fuel pressure gauge installed in an SRT/10 A-pillar last week, I was surprised to see it go to zero so easily with my EDGE on #4. I never noticed any running problems with "zero" fuel pressure, but it certainly used to make me wonder after running without a fuel pressure gauge for so long. Since the service manual supposedly has no specs regarding pressure but have specs for volume, I'm not going to worry an awful lot about it, unless more mods come & I run into a fuel starvation problem.

Greg

 

[rbattelle]

In the early days of the 2003 trucks the early service manuals had a specification of 9. 5 psi minimum LP pressure at idle. I happen to own a manual that says that. Very quickly, however, Dodge issued a new corrected service manual that removed all references to minimum LP pressure and instead substituted a flow rate requirement. As far as I know, you can no longer purchase a service manual for the 3rd gen trucks that lists a minimum pressure spec on the diesel lift pump.



-Ryan

 

[Wayne M.]

Is anyone using the metal filter cap from geno's with the port on it as a pressure take off? I read elsewhere here that the euro version of this CRD system as installed in other vehicles dosen't use a lift pump at all.

 

[Jengle]

Mine reads about 7-8 at idle in warm weather, drops to about 5-6 in cold, below 32. Driving sits steady on 5, but can suck it down to zero with a hard flog. Stock settings, the lowest I have seen is 5, but with the box turned up it will stumble on 0. This is measured post filter. Need a pump. Soon.

 

[bpenrod]

I have the billet cover on my truck and that is where I am getting my pressure readings from now.