Engine/Transmission (1998.5 - 2002) 15# pusher pump

[Straight6Jeff]

OK, I know there are 7# pusher pumps being used in conjunction with the stock pump in the stock locaction, but would there be a detriment to using a 15# pump as a pusher and the stock pump in the stock location. The pusher would be wired with a relay and on all the time (ignition-on), meaning it would not pulse like the stock pump on startup.



just thinking... .

 

[keimmmo]

I am using a pusher pump just like you describe. I have around 30 lbs pressure with motor off and pumps on. If I wait for the original pump to cycle off, the pressure drops to 10-15 for startup. I cruse at 20-25 lbs. I NEVER see less than 15 at full throttle! I have concluded the original pump increases the pressure by about 15 lbs above what it sees at the inlet.



I also have a big spin-on pre-filter under the truck. I wanted the higher pressure to push the fuel through the filter. I really have more pressure than I wanted, but it doesn't seem to be causing problems.



I lost a VP-44 from low pressure. I wanted to be sure I had enough this time... I think I succeeded! From what I have read, the only likely problem is hard starting hot. If I try to start it with 30 lbs, it sometimes doesn't fire like it should. If I wait for the pressure to drop below 15 lbs, it fires like it should every time.



I have been modifying vehicles for over 30 years. I have pretty well concluded that every time you make a modification to solve a problem, you create two new problems. (Give or take) Everything is a trade off. You just have to decide what you can and can not live with.



Steve

 

[Straight6Jeff]

I like the idea of a spin on filter. WOuld the pusher be too much restriction to fire the truck with the pusher turned off, then after firing it up, turn on the pusher?

 

[HeberRam]

My recommendation!!

Sj... if you are planning on installing a pusher pump in line with the stock, some vendors sell these kits... I would NOT recommend installing the #15 lb. pump with the stock pump... go with the #7 lb. Combined pressure at idle (depending) on mods. should put you in the 19-22psi range on your gauge. exceeding more then that, can be detrimental to the VP-44 injection pump and could cause premature failure. In the case of the VP-44 fuel injection pump, everyone knows not enough is good, however, alot of people don't know tooo much is no good either.



Steve

 

[keimmmo]

I know my pressures are on the high side. I would really like to drop them a little. But, I was concerned about pushing the fuel through the spin-on at full throttle when I installed my present system. I would be concerned about firing the motor without shoving a little fuel through the spin-on first... maybe it would happen so fast that it wouldn't matter.



What I would really like to do is run a 15# pusher into a 7# in the factory position. That way I would have plenty of pressure to shove the fuel through the spin-on and then give it a little boost up at the motor. The factory pumps seem to add their rated pressure to what they see at the inlet.



For you fellows who have taken apart dead lift pumps... is there a way to modify the pressure relief valve on a factory LP to make it a lower pressure pump?



Steve

 

[EricBu12]

I did the stock pump and a 7# pump and I also put in a mechanical Regulator that is adjusted with a spring and bolt. I can keep my system in 11-13 range NO MATTER WHAT... I have 331 hp at the wheels and 29 psi boost and idle 13 psi WOT 11 ... . not bad. I also have a prefilter and a bypass around the pusher if it ever fails.....



Also put in a 18 gal Aux tank in the spare location and used an old LP to transfer the fuel from the aux to main tank by way of a Aux fitting that is capped on the main tank unit... .

 

[ToolManTimTaylor]

Originally posted by keimmmo





I lost a VP-44 from low pressure. Steve

Careful as you WILL lose one to HIGH pressure. 26# seems to be the magic threshold +- 2 lbs. At 30 you are THERE! EmDiesel I think lost one to 32 lbs (Internal failure). However with your spin on setup I think if anything flow is reduced as pressure is pressure.



Run an external regulator up by the VP and you should be golden.





Jeff , I think Bill (IllFlem) Responded to one of my posts that described the way the pulse works as I was curious how even tho it is MUCH bigger how My PE4200 makes the required 12 Lbs at startup and I have it wired with a relay. I will look for the post.

 

[keimmmo]

Using a regulator had crossed my mind. Where do I get one and how much do they cost? I would still be interested in how the valve works inside the lift pump... might be able to lower the pressure the pumps produce and still have the volumn.



Yes, I would say my first problem was more a matter of volumn than actual pressure. I had adequate pressure at idle and low speeds, but it fell to zero if I even crowded the throttle.



I live in central Mexico most of the time and dirty fuel is a problem. I also add drain oil to my fuel and want to be sure nothing gets through to the injection pump. Removing the extra filter is not an option in my opinion! I need to find a way to make things work WITH the filter!



Thanks for any help you can give.



Steve

 

[ToolManTimTaylor]

Originally posted by keimmmo

Using a regulator had crossed my mind. Where do I get one and how much do they cost? I would still be interested in how the valve works inside the lift pump... might be able to lower the pressure the pumps produce and still have the volumn.

Steve

Here's one of 'em



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=22387



Sorry jeff back to YOU No hijackin' here nope nuh uh no way.

 

[canblue]

Heater needed for second filter?

If I install an additional pusher, 7#, and a filter, do I need a fuel heater to contend with fuel gelling? Can an additional filter/heater combo(DC's unit) be added to the system without problems? What check mechanism can be installed to monitor the 2 pumps other than FP? If the DC pusher/sucker goes south, how would one know this? Will the secondary pump be able to carry the load?

 

[EricBu12]

On the pusher pump, I used a bypass with a one way check valve so if the Pusher failed, the stock one could draw around the pump from the filter.



It would still have the small head pressure from the regulator.



The racor pre-filter I bought is connected to the swiched side of the relay for the stock fuel heater so if the stock one comes on, the racor will as well.



There is also 2 sensors on it that go to a LED warning system to let me know if there is water in the separator and if the filter is getting clogged.



I see 13 idle and no less than 11 or 12 even at WOT. ( I have 2 boxes... )