Engine/Transmission (1998.5 - 2002) Fuel Filter micron rating/FASS/VP question..

[JCyrbok]

I have a FASS on my truck and it has worked out well for me the past 2 years. I have been running the NAPA 1724 filter which is a 10micron (despite what was initially post on TDR about it being 1 micron) hydralic filter like the stock one. Recently I bought a fleetgaurd filter that is 6micron because I had seen that Cummins changed the miron spec with the ULSD intro. The 6 micron filter has yet to be installed.



I have heard conflicting info on whether this spec change is for all engines or just the newer common rail ones. Knowing full well and first hand that lack of fuel flow to the VP will kill it, I am wondering if going to the 6micron filter could actually be determential to the VP despite the higher filter rating. Worried that the tighter media will flow less volume per hour and starve the VP. FP is 15. 5 at idle and 14. 5ish at highway (80mph) speeds, but have always been able to pull it down to about 13. 5 WOT ( I have been procratstinating on either a draw straw or pick up modification)



Any Idea's? I am prob gonna change out filters today, or atleast this weekend as my FP is dropping sligthly, with the current filter that has about 15K on it (this was a pre ULSD filter too, so it may be gunking up early)



Any helps/ideas would be greatly appreciated.



Thanks

J-

 

[sgoeing]

I'm pullling my FASS down to about 12 psi now on my 99.

I got a 10 micron cellulose by WIX from O'reilly's pretty cheap, because they had it in stock. So that's what I'm changing to this weekend.


I'm sure you'll be fine at 6. My fass came with 10, and that's what I'll stick with probably. Especially now that I know the place right down the road has it in stock.

 

[DCreed]

the VP doesnt starve untill 5psi ,if youre seeing 12 @WOT i wouldnt worry too much.

 

[sgoeing]

I just worry a bit about the stress on the fass. When it's been at 16 WOT and 18 idle, and now it's at 15 and 12, that tells me it's working a bit harder than necessary.

 

[AFarmer]

Sounds like you'll be just fine. Filtration level is much more important on the 3rd gen's over the 2nd gen's. 10 micron is good but 6 is better but not a must. As long as you stay over 10lbs IMO you'll be just fine.

 

[Joe Mc]

So if I understand a 10 is good and 6 is better. This being the case higher number allows smaller micron particals to pass - yes?

Maybe that's why Glacier Diesel supplies a 2 micron with their spin on filter kit. Have had mine for about a year now and on the second filter - only put on less than 10 k a year unless we go cross country.