Camarogenius

Well, what I thought was a FASS pump on my truck wasn't, or isn't any longer. Long story, for a later date.
I've been looking at options, and the local farm supply store has 12V pumps, suitable for oil and chemicals.
They're rated at 150 GPH, at 50 PSI. The thing looks like a Chevy starter. It's huge!! They're also 100% duty cycle, and less than $200.
Is this a good idea, or no? They're originally intended for sprayers.

Jordan5687

I'm pretty interested in finding out about this myself. I had looked at it before I bought my Walbro. Hope someone chimes in about this. If I ever have to replace my pump, I'd look into this better.

zulusafari

way overkill. Your truck needs 42 or so GPH for fueling and coolant at maximum load, stock. No reason for that type of pump. I installed a Walbro GSL 392 I ordered off of ebay, $120 shipped, with correct size hose barb fittings. Some simple wiring with a Lift Pump Relay harness I bought from Vulcan Performance, and a slick Swagelok bypass valve, and I have PEELENTY of fuel for my VP44, and 15 - 20 PSI at all times. Since I used the stock ECM signal to trigger the relay, I get the same delayed pump run startup so no hard starting. Pressure builds fast, and I have moved my FP gauge pre-filter to monitor filter life, and installed a low FP light at the VP inlet port to monitor any issues with post filter low pressure. At this point, it would take a line or fitting failure to drop fuel pressure low enough to trigger the light while I am driving. I had a leaking fitting following the install, and I was able to watch the fuel pressure swing, but never below 12 psi. I recommend the Walbro!

Jordan5687

Yeah, I'm quite pleased with my set up too. But I can't get any more pressure than about 15psi, and min of 12.

zulusafari

My Swagelok was about $22 shipped. It is adjustable from 3 - 50 psi, and I installed it in a tapped 90* 08JIC fitting from Vulcan Performance. If I hadn't decided to change out all the fittings on the Fuel Filter Canister, bypassing the stock POS Lift Pump, my install would have been much cheaper. I ran the bypass line back to the fuel tank filler vent line, using black iron and brass fittings I bought at my local hardware store. Between the fittings, fuel line, and wiring harness from Vulcan, along with the Swagelock bypass and local fittings, I have approx. $200 extra above the $120 shipped on the Walbro. This puts me below the Glacier GSL 391 kit in the performance shop on this site, and I replaced more fuel lines and fittings. I did not step up to 1/2 inch line, because I feel I have plenty of fuel for my truck with stock 3/8ths and 5/16ths return. I can easily upgrade later, but I would need to be running a TON more horsepower before it would be remotely required. I could also have saved several bucks if I had wired up my own relay harness, but the Vulcan one wasn't outrageous, it was complete and nicely manufactured, and was really simple to install. I am no longer worried about the lift pump system on my truck and how long it will feed my new VP44 from MWFI!!

zulusafari

That pressure is fine, but where is your regulator? I am in agreement with a former member that the bypass really needs to be at the VP44 inlet, nowhere else. This way, the full fuel flow from the Walbro is allowed to go past the inlet on the VP, before being bled back to the tank. This also allows all the fuel to be filtered before returning to the tank, so fuel is filtered the first pass through the Walbro, extending the life. I was nervous of some of the well developed kits for sale, since they incorporated the bypass right after the pump discharge, for a nice compact installation. But what if the bypass is sticking, or the fuel filter is getting dirty? Then the increased fuel pressure is bled back to the tank, with less going to the VP44. I know we can measure the pressure post filter to be sure, but why not let all the fuel flow past the VP inlet anyway? I can monitor the condition of my fuel filter with my pre-filter guage, since the PSI required will increase, indicating my filter is plugging. I know my bypass regulator will not open before 15 psi, so if the lid isn't broken on my filter housing or a line broken, I am pumping at least 15 psi to the inlet at all times. I get 20 PSI at idle due to the increased return flow and back pressure over running WFO.

Seriously, your pressure looks great. My stock LP and its stock replacement would idle at 13-14, and would go to 10 at 3/4 throttle jack-rabbit starts. In really cold weather, it would drop to 5 psi easily, due to cold filter plugging, until the engine bay and fuel heater warmed enough. I use Power Service white each tank, but it was pretty cold here several days this winter (not Canada cold, but well below zero.) Which Walbro setup did you go with?
Edit: I see it in you signature. Doh!

zulusafari

After all that, I don't think I answered your question!! General feeling is much over approx. 15-20 PSI is unnecessary for the VP44, and will actually cause hard starting. With the 50 PSI pump you would need to run a bypass of some sort, like the Swagelok mentioned previously, to bleed fuel pressure off to the tank that isn't needed for the VP. This should increase the life of the pump, since it isn't forced to run at a 50 psi head pressure anymore. Try to get a pump curve for the unit, and see what it flows at 15 psi! I bet it is over 200 GPH, which again is WAY WAY more than we need. For the money, there are better options out there, as in sized a bit closer to what we require for power and pump cooling. Other factors may eliminate the sprayer pump as well. Most I have seen are rated for many chemicals and oils, but not for diesel fuel. I ran into a lot of that for my biodiesel investigating. Also, is the pump suited for mounting under your truck? Some are used in pretty severe service on ag equipment, but others are housed in nice enclosures or on the outer surfaces on equipment reserved for fair weather use. Just throwing out variables. Not trying to sound like a know-it-all here. That pump may be the next big BOMB, or it may just be another good mental excercise in the quest for the ultimate lift pump upgrade!!

Jester

The flow rating is fine, but the pressure will blow the diaphragm on the inlet to the VP44. I recall reading that 20psi is the max inlet pressure for a VP44.

zulu,

Can you explain how placing your fuel pressure gauge before the filter aids you in monitoring filter life? I think you have your lines seriously crossed.

sleepr tsi

I was wondering the same thing, I would guess the drop in pressure would indicate filter clog.

Although, I would think it be important to see what the injection pump is getting...

gies

At one point I had concerns about too much pressure. This quote below is from "the man" in my opinion. Don is talking about the 12v lift pump used on his cam for 24v engines:

zulusafari

By having the gauge pre-filter, and knowing what my fuel pressure is with a brand new filter element with my system, if the pressure begins to increase I know I have a filter plugging since it will exert more backpressure on the fuel line. Since I have a lift pump capable of 100 psi, I wanted to be sure I do not increase fuel pressure too much since approx. 60 PSI has been shown to be about all the stock plastic filter housing lid can handle. If the element were to clog due to wax or other cold weather conditions (I live in Iowa) then I could concievably push 100 psi with my lift pump and would only see 15 PSI post filter to the VP44 if the regulator opened.

Clear as mud yet??


I forgot about that post from Don M, who I also highly respect. It was his advice on when the HRVP's make sense that convinced me I would do better with an SO VP44 on my truck. Most posts I have read seemed to indicate blowing the diaphragm is much more likely due to LOW pressure at the VP44, but I am sure there must be an upper limit as well. I have read that the blown diaphragm combined with a sticking/leaking timing piston is usually cause for the P0216 code, and is why the pump can continue to run for a long time albeit with decreasing economy and power. My pump lasted for approx. 18 months or so before I replaced it.

high country

I have seen two failures of the vp44 at 30+ psi. the two were identical and ironicly I was towing a buddies truck that puked when mine bit it. both pumps poped the seal between the vp44 and timing case. that seal is a steel w/ viton and has never been known to fail......or so my bosch buddy says. he inquired at a builders meeting and the two seals seem to be isolated.....bizzare. 30 plus psi is not going to affect your starting if you use the stock system to trigger your lift pumps or use the mech pump as it is at 0 psi till it turns over. what causes hard starting is too much pressure before ignition.....that can do it for sure. I have continued to run 40ish psi on my truck and no failures, my buddy is all kinds of gun shy and he runs 12 psi. I feel like it must have been voodoo or some crazy devine deal to have the two trucks puke in series like that. we had nothing in common aside from fuel pressure.

dsl kicks gas

i ran a procomp black(150gph@17psi) and it was trigered off the ecm. it ran 17psi at a idle and never droped below 16 at WOT. the problem was that it blew the seal in the top of the pump(lift pump) and filled the motor with fuel.....long story short i had my old stocl lp that was drilled and taped to 3/8 that i put back on it and have been drivin it like that for about a month.

i'm going to get a holley blue pump to put back on it. do yall think that would be fine, or may it have the same problems as the procomp?


i think 50psi would be to much, ad like said before it probley runs at over 200gph :2cents

cLAYH

I'm running 29psi at idle, with a Holley blue pushing into the stock pump. Its triggered off of the stock LP wiring harness and there is no problem with starting. Been running that way for 5 months now.

2whistlers

How would say a Carter 4601HP pump or Holley Black pump run if bypassing the stock lift pump altogether? I have thought about doing this with my Carter but am not sure it will support the fuel demands by itself. I just don't like the idea of more than one pump, myself.

Thanks,

Rodney