Goodbye pusher pump

[EMDDIESEL]

I just bypassed my pusher pump on my 01'. I left it in place, but disconnected the hoses and ran a new one around it. I am not comfortable having 24psi at idle and 16 at WOT. All my fuel lines are stock including my Banjos, i cant imagine what the pressure would be if i had larger lines with AN fittings. I do not want to have problems with the injection pump blowing seals or what not. I am more then happy with 16psi on my stock (except for an EZ) truck. I can now relax without fears of trashing something.



I am leaving the pusher pump in place, just putting pipe plugs in it so if and when i need it, or somebody has concrete proof that fuel pressure as high as 24psi at idle is acceptable, i can re connect it. I dont want to void my warranty, so re plumbing any fuel lines in the engine compartment with return lines and regulators is out of the question.

If anybody hears any good news on this subject, let me know. Untill then, i will deal with lift pump replacments every year if nessecary.

 

[Evan A. Beck]

Actually, with the modified fittings and/or hose, your flow will increase, and your pressure may drop... Remember, pressure, be definition is a resistance to flow. May want to try connecting up a set of Aeroquip lines and hooking up the pusher pump again... Good plan on leaving it in though, just in case.

 

[Steve St.Laurent]

Not that I'm trying to talk you out of your decision by any means but I thought you might like to know this. Bill K has posted that he tried fuel pressures up to 60 psi (I believe that's correct - please correct me if I'm wrong Bill!) and Mark Chapple from TST has told me that he tested up to the same numbers. Neither of them blew out any seals in the VP44 that they've posted. If that's the case then 24 psi would be no problem. I asked both a Cummins and DC engineers responsable for our trucks and both said no problem at 22 psi (which is 2 psi above what I see as a max).

 

[Shooter]

I have 6-an fuel lines and mine maxes at 18# and bottoms out at 16#. No problems starting cold , 45*, or hot, 100+*, starts on first compression stroke, no cranking just touch the starter.

 

[Steve St.Laurent]

I just went back and found that post from Bill K. He did in fact run the VP44 with 20, 30, 40, 50 and 60 psi at the inlet. He didn't see any increase in return flow to the tank but he also did not blow out the seal on the shaft of the VP44. Mark Chapple also ran one at up to 60 psi and did testing on a dyno and didn't see any increase in power on the dyno. The point here is that two guys have run up to 60 psi into the pump without blowing that seal out which is the primary concern. If it can hold 60 psi even for a short period of time then 24 psi is no problem.



-Steve

 

[MidwestMotorman]

thanks...

Thanks for the info Steve. I recently lost my lift pump and had to wire in a pusher so I could run the truck without too much damage to the VP44. I tried a Holley Blue High Performance pump (without the regulator) I had laying around. I hooked it up and ran the engine. I had to shut the thing off as it kept climbing and I was worried when it hit 35 psi and did not look like it was going to stop.



I just left a regular automotive one in that made five psi until the dealer got me one in.

 

[Un-Hemi]

Nathan, it sounds like the regulator in the Holley Blue wasn't working. Aren't they supposed to supply about 15psi? It's been so long since I rebuilt the one I have that I have forgotten the specs!

 

[MidwestMotorman]

holley

The regulator comes seperate on the blue pumps, and I did not have one on it. I have just used the pump to siphon fuel, drain tanks, and prime the fuel pump/carbs on cars. I just ran the pump to see what it would do, as they are supposed to be a 13 psi pump. Apparently the regulator is a must have thing for the blue pump, as the pressure can build up over 35 psi (even with the truck running!)