Engine/Transmission (1998.5 - 2002) Is hindsight 20/20? Fuel Filter Issue

[Deezal Man]

Driving to work I noticed a light stumble on the hills. Unfortunately I had no choice but to drive on, so I maintained light throttle and all seemed well. Once I arrived I noticed my fuel pressure gauge, mounted on the output side of the fuel filter housing was down to 10 psi so I assumed this was nothing more than a dirty fuel filter. Easy enough to fix but not before driving 75 miles home that evening. I had no filter, no tools and besides. . I was wearing a white shirt and tie for work that day.



Well, About 55 miles into the drive home, my plan fell apart. I literally had to drive with the 4 way flashers and keep it below 40 mph. At this point, fuel pressure was 5 psi at idle. Being on a busy highway in rush hour traffic, I had two choices. Keep going or call a tow. I decided to limp home and investigate the situation myself. I guess I assumed the worst and figured the VP44 was trash anyway. . so might as well get it home. Otherwise, it would end up at a dealer... and we all know what that would have meant. Replace parts till we find the problem.



Anyway, once home I proceeded to change the filter. to my surprise this did not fix the problem. Then I remembered the little 'pre-screen' filter in the banjo bolt for the DDRP FASS fuel pump. Let's just say, I'm impressed the truck ran at all. It was completely blocked with all kinds of little particles. I plan to call FASS later today to understand the impact of removing this screen.



We all know what happens to the VP44 when it's starved of fuel but I don't know if this damage happens instantly. So my question to you is, what kind of damage did I do to the VP44 driving 20 miles in a very low pressure condition. In hindsight I'm questioning my decision to drive home.

 

[98whitelightnin]

Your pump will be fine, most drive around alot longer than that without the vp dieing to fast. Its a vp and will eventually die no matter what you do. I run an inline filter before my fass 150hpfp but I do have rubber lines from the tank.

 

[PVanderlugt]

I would agree as well that you would be fine, before we started to monitor fuel pressure people were driving for 1000's of miles without knowing any better. The VP goes when it wants to, fuel pressure is only part of the equation.
Pete

 

[Deezal Man]

I gotta tell ya, hearing and feeling the truck stumble for 20 miles was among the "longest" rides home I've had in a while. It felt just like running out of fuel because... well... in a sense it was. I've heard stories about this but experiencing it put a whole new perspective to it.



So let me ask this. How dioes a person drive hundreds or thousands of miles with low fuel pressure? Mine at 5 PSI was literally was not driveable in a normal fashion. Crazy!

 

[ALoehr]

normally, people w/o a gauge installed will never know that the transfer pump has died in its sleep unless they normally call for large amounts of power and will notice a power loss, or notice a slightly longer crank during start up. The VP44 will run (for a while) without ample supply pressure as long as there is not a line restriction, such as your case. most "turn the key and go" drivers only notice there is a problem once the truck quits running, and has done so because the inj. pump needs supply pressure and does not like drawing fuel through its own vacuum. the VP uses fuel to cool itself, so without at least 10 psi on a regular basis, and no less than 5 psi @ WOT, it will eventually hand in a resignation letter. So far (knock on wood) I have 240k on my original VP without any problems. use a GOOD fuel additive, I use a product called BTU+ TOTAL TREAT, from Lubrication Engineers, pruduct number 2410. you cannot buy it on a store shelf so get on thier website and look up a local rep and give him a call. Lubrication Engineers - Locator

 

[AH64ID]

I would remove the screen and put a BF1212 in the suction fuel line on a FB1311 filter head. This will pre-filter your fuel for the pump and provide additional water separation.

 

[Deezal Man]

Ironically, FASS never returned my call or responded to my e-mail regarding the subject matter.



In any event. . I don't want to belabor the issue but to be clear. The injector pump and fuel pump were both starving for fuel to the point I had to constantly back off the throttle to prevent it from "bucking". That is what prevented me from driving faster than 40 mph (less on a hill). Things were way beyond loss of power. I was praying the truck would be able to get me home... regardless of speed. (10mph if necessary)



FWIW, when I installed the DDRP pump, fuel pressure was 13-14 psi. Without the screen, it's holding a constant 15-16 psi. I think I'll take my chances on the fuel pump and continue to monitor the output pressure gauge. For now... .

 

[ALoehr]

If FASS runs the fuel through the pump before the filters they may have installed that prescreen to keep paticles large enough to harm the pump out of the mix, so you may void your FASS warranty with it removed.

 

[AH64ID]

If FASS runs the fuel through the pump before the filters they may have installed that prescreen to keep paticles large enough to harm the pump out of the mix, so you may void your FASS warranty with it removed.

Which is why I would install a BF1212 on a FB1311 pre-pump.