Engine/Transmission (1998.5 - 2002) 95gph FASS installed w/only 9psi...why?

[Casey Ray]

ok guys, just put the 95gph FASS on this weekend too. so far (5 miles) it is great... and really quiet (compared to my old PE 4200 that died) anyhow, i did not plumb thru the OEM filter canister, the instructions said to plumb the discharge of the FASS to the input of the VP44 with the provided adapter and plumbing. so i did. i thought the idea of the FASS with its filtering and stuff was to completely bypass the stock filter. i have been reading the posts, and it seems that most of you are still using the stock filter, why???

jkern,



All depends on what model of FASS you have. FASS I has the filters built into the pump housing. FASS II is the stand alone fuel pump. If you have the FASS II you need to plumb through the original fuel filter for filtering or you will be pumping unfiltered fuel to your VP44.



Casey

 

[JimKing]

Got my FASS on today, it was one of the units with the new spring in it. 22 psi at idle?!?!?!?!?!?



Better compress the spring a bit. At 22 psi it may not start hot. Mine really likes 16. I bypassed the filter altogether and go direct to the VP.

 

[Casey Ray]

You guys bypassing the filter with the FASS II should check out the Installation Manual; STEP 3, (Installing Fuel Line part 4, with this Note: "The inlet side to the fuel filter may be on top as seen in photo 3A or on the side as seen in photo 3B. " Part 4 states: "Disconnect factory fuel line from inlet side of factory fuel filter and install the injection pump o'ring fuel (part# DIPF-1001) fitting into this inlet port. This is the banjo fiting in photo 3A (or 3B). Torque to proper specifications. " By bypassing the fuel filter and going directly to the VP44, without any type of fuel filtering, is pumping unfiltered fuel directly into your VP44. I am by no means an expert on the VP44, but I am sure pumping unfiltered diesel through it will only shorten it's life. I post this so that I can possibly help someone save their VP44.



As for the fuel pressure, I'm seeing 22 psi at idle, drove the truck a couple of hundred miles last night, started right up with no problems after a couple of short stops and a fillup. Guess time will tell if it becomes a problem.



Hope this helps abit.



cul,



Casey

 

[Oil Burner]

definately run a filter! Your pump will take a beating, and the injectors will clog. If you want the benefit of the full -6 system, you can buy the fittings from summit and run the line from the filter to the pump.



Maybe he meant that he bought the full FASS sytem with filters and bypassed the factory filter???



Jason

 

[SKargo]

Got my FASS on today, it was one of the units with the new spring in it. 22 psi at idle?!?!?!?!?!?



Better compress the spring a bit. At 22 psi it may not start hot. Mine really likes 16. I bypassed the filter altogether and go direct to the VP.

So what is filtering your fuel then?



I have had mine on since Thursday at 22 psi at idle, no problems whatsoever. If anything, it starts up quicker.



It sounds a little different, even my wife noticed that, and I could swear it's a hair more responsive. I'll fill up tomorrow and check my mileage. This thing is screamin for some injectors now.

 

[JRagland]

Most of this confusion is from not explaining which FASS each person is using. The full FASS system has its own filtering unit, including air-fuel separator, so it can either bypass the stock filter, or use it. The newer FASS II that this thread was started about, is only a pump, no filter, and must use the stock filter. It is the same pump from the full FASS, but does not have a filter.

 

[JimKing]

Let's see here. directions are:

Place large boot on foot, either will do nicely

Check torque on laces, tighten to 10 Ft/3

Open mouth, wider the better

Insert boot. .



I have the Fass WITH filter(s) I run the 2 micron filter. .



There is a thread about pressure and the VP. MY personal experience was less than wonderful at higher pressure. Ran great, wouldn't start when hot unless I allowed the pressure to bleed way down, 10 seconds or more after turning on the key.



Sorry about the confusion. .

 

[SKargo]

No problem Jim. What causes the hot start problem?

 

[JimKing]

Somewhere on this site there is a thread concerning lift pump pressure and hot start problems. I am not sure where the thread is.



When I exceeded 16 lbs on mine it would not start when hot... Ran great at 22 lbs but sounded funny, sort of "less rattily" for lack of a better term. I seem to remember that someone said 20 or 22 lbs can damage the VP... Don't remember where I heard that either...