Engine/Transmission (1998.5 - 2002) can you use Fuel pressure gauge to determine filter life?

[jkidd]

can you use Fuel pressure gauge to determine filter life?



Most people change the fuel filter at 10k miles. If your fuel pressure at idle and WOT are still the same or within 1 PSI?



Why change before it is needed?



Any thoughts/ experience?

 

[Thomas]

can you use Fuel pressure gauge to determine filter life?



Most people change the fuel filter at 10k miles. If your fuel pressure at idle and WOT are still the same or within 1 PSI?



Why change before it is needed?



Any thoughts/ experience?

I run two fuel pressure gauges & two senders full time to monitor fuel pressure both before and after the water separator/fuel filter on my model year 2000 Cummins/Ram.



I have yet (more than 100,000 miles) to see a difference between the two gauges. The Factory Service Manuals for the ISB equipped Rams allow a "Fuel Pressure Drop Across Fuel Filter Test Ports 34 kPa max. (5 psi. max. ) at 2500 rpm (rated rpm)".



On the other hand, I've experienced various differences between idle fuel pressures and WOT fuel pressures, as great as ten psi. I interpretted the difference as indicating a dying transfer pump - not a clogged filter.

 

[rweis]

I had gauges pre and post filter as well. I found tht the gauge/sensor system is not accurate enough from gauge/sensor to gauge/sensor to be able to reliably/consistantly tell a drop of one or two psi.



Maybe if you could switch the same gauge/sensor from pre to post that might work, but as soon as you introduce the second sensor/gauge package you introduce variables that render very fine granular comparisons not consistent.



I use mine as yes there is adequate psi on both for the VP44 to function psi wise and I know the lines are all AN-6 (only DC fuel lines left on my truck are from the VP44 relief valve to the engine T, and from the injector gallary to the engine T, and the actual engine T itself) so the volume needed is there as well.



I have had a fuel psi sensor fail and rather than think the VP44 was not getting fed, the second gauge package showed the psi was still there (worth its weight in gold).



Bob Weis

 

[FYarcho]

I too also run pre and post filter guages. I religiously change my fuel filter every other oil change. I have to agree with the other two posts. I think you would have to have a really plugged filter in order to show a substantial change. But it sure is nice to have the back up guage to know for sure where your pressures are.

 

[NoSeeUm]

Filters often tend to have a nasty habit of once they begin to show D/P (plug) they will completely plug rapidly there after.



Jim

 

[WestTN]

I run 1 Westech gauge and 2 sensors, using a toggle switch to check before and after filter pressure. This will provide instant answers in the evnet of a problem.



A filter will only plug rapidly if there is contamination in the fuel to plug it.

 

[Bob Cochran]

Monitor fuel pressure after fuel filter and change the filter at 7500 miles. Makes me feel more comfortable doing that.

 

[jkidd]

Sounds like there is not a reliable way to tell when it is getting clogged and would need changing. I will stick to the schedule.

Thanks

Jacob

 

[WestTN]

I have found that for my truck, my dual sensors work just fine. Of course, I have 122,200 miles on it and have NEVER found a drop of water in the system. Ever! My fuel has always been clean except for 1 single fillup.



I finally gave up and changed the last filter a few days ago. It had about 15,000 miles on it and only 1 psi more pressure differential across it than a new filter.



I'm building up a small box of unused fuel filters from buying the 4-2-1 kit from Geno's.

 

[SHobbs]

The last few days fuel pressure at idle has slowly been droppin, usually 12psi at idle. Today it was 9psi at idle and at half throttle it would drop to 5 or below can't have that. Changed the filter and all is back to normal, 12psi at idle never below 8 at WOT. I have always gone by the guage. Can I get more out of the filter, maybe but when it starts to get close to 5psi at WOT or half throttle even it's time to change it. I hardly worry about the mileage, pressure is more important to me, filters are cheap compared to VP44's.