Engine/Transmission (1998.5 - 2002) Fuel Filter

[Wolfgang]

Has anyone ever bypassed the stock filter with another setup. I get a big fuel pressure loss through my filter and can't figure out why. I have replaced the filter 3 times with no change. It is like I have a blockage in the cannister some place

 

[Thomas]

How are you measuring the loss?

 

[Wolfgang]

With Briar Hoppers gauge pre filter and at the VP 44. I also have installed a permanent gauge at the VP44

 

[CWade]

There is always some pressure loss, because a filter is a restriction. Will have to look in my book at work to see what the Cummins specs allow. I am guessing that 3-5 psi difference may be normal.



Charlie



P. S. I have an owner's manual here for a first generation B engine and it's showing a maximum of 5 psi drop across the filter

 

[Thomas]

The model year 2000 factory service manual allows up to a 5 psi difference between the two test ports. That being said, I have never seen more than a 1 psi difference between the inlet and outlet of the filter cannister. I have a full-time dual gauge setup.



What kind of drop are you seeing across the filter?

 

[Wolfgang]

I see at least a 5 psi drop sometimes more. Most of the posts I have read the people claim to not see anything below 8 psi WOT. Maybe they are reading Prefilter?

 

[RustyJC]

I also have a dual fuel pressure gauge reading pre-filter and post-filter pressures. With ambient temperatures around 50 degF or lower (a cold day in Houston), I'll see 16 psig pre-filter and 10-11 psig post-filter on a cold start, but within a minute or so pressures have equalized at idle such that I see 16 psig on both gauges. At WOT towing our 5th wheel, I might typically see 1 or at most 2 psig difference between pre-filter and post-filter fuel pressure - around 12 psig pre-filter and 10-11 psig post-filter.



Rusty

 

[Wolfgang]

This is why I am wondering if I may have a restriction in my filter housing. I worry that I am pulling my pressure down to much at the VP44