Engine/Transmission (1998.5 - 2002) Fuel Pressure Conflicts

[turbo torque]

Fuel pressure has always been 12-13lb recently dropped to 7lb, now 5-6lb.

I have an electronic westach gauge post filter. I suspected lift pump or filter getting plugged but, only 2k on new filter.



Today I put a snap-on mechanical gauge pre-filter and get 14-15lb.

OK, changed out filter, it looked brand new but, what the heck, this new ULSD and all.



Well I got 14-15lb pre filter. What gives? I have a grease gun hose for a snubber on the westach gauge, could this be deteriating and imploding resulting in a lower reading, I doubt it. What else? a bad sending unit?



The sending unit did start leaking, (real bad) where the wires come out the top. I took nuts and washers off the terminals and applyed a thin smear of ultra-black silicone to the washers and let cure for about 15 min , reassembled and no more leaks.



What do you guys think?? sending unit? I don't see what else it could be.



I hate seeing 5 lb, makes me nervous.

 

[blacksheepdiesel]

turbo torque,

Sounds like you answered your own question to me. If the sender was leaking it needs replaced.

Godspeed,
Trent

 

[Detroitiron]

am I reading this right?

Fuel pressure has always been 12-13lb recently dropped to 7lb, now 5-6lb.

I have an electronic westach gauge post filter. I suspected lift pump or filter getting plugged but, only 2k on new filter.



Today I put a snap-on mechanical gauge pre-filter and get 14-15lb.

OK, changed out filter, it looked brand new but, what the heck, this new ULSD and all.



Well I got 14-15lb pre filter. What gives? I have a grease gun hose for a snubber on the westach gauge, could this be deteriating and imploding resulting in a lower reading, I doubt it. What else? a bad sending unit?



The sending unit did start leaking, (real bad) where the wires come out the top. I took nuts and washers off the terminals and applyed a thin smear of ultra-black silicone to the washers and let cure for about 15 min , reassembled and no more leaks.



What do you guys think?? sending unit? I don't see what else it could be.



I hate seeing 5 lb, makes me nervous.

You had 14-15 PSI pre-filter on the Westach gauge and on the Snap On gauge. Then you changed the filter. Now you have 14-15 PSI on the gauge, still pre-filter. Logic forces me to ask, if before filter change and after filter change, readings were the same, and the readings were taken before the filter, how could you tell if the filter was the cause of the pressure drop? Was it a typo? A reading before, (Schrader valve on filter housing) and after (Schrader valve on VP-44), the filter would determine if there was a pressure drop caused by the filter, or did I miss something here? I'm not finding fault, not picking nits, but reading your post makes me wonder how you determined, or rather if you determined that the filter was causing a pressure loss. Or was that not what you discovered? Will your mechanical gauge threads fit the Schrader valve on the VP-44? I hope you figure it out, I know from experience how frustrating it can be. My Westach gauge is attached to the Schrader valve on the VP-44, (via the hose kit from Geno's), so I'm reading what the VP-44 actually 'sees' for fuel pressure.



best of luck,



Dave

 

[GCULP]

ditto on the pressure reading before the filter, should be reading from both sides of the filter with the same guage to determine if the filter is the problem. after all that, I think you're sender is bad, silicone may have stopped the leak, but it won't fix the internals that are bad. Let us know what fixed it.

 

[ACoyle]

I have to agree that once the sender leaks, It can only be considered fixed when the garbage truck takes it away.



It needs to be replaced. Once that is done, the question as to the grease gun hose will be selg answering. Correct pressure equals hose OK low reading equals replace hose. Keep going till the guage closely matches the mechanical.



Just an unrelated thought here. If one were to put a sender before and after the filter, It would be possible to read pressure drop across the filter. I think Steve did this. If memory serves, he had some great pix up.



Taking that a bit further, one of our electronics people on the boatr might be able to give us a circuit that watched the difference and gave an indication at a certain differential to change filters.



AC

 

[Detroitiron]

turbo torque, I goofed...sorry about that..

Fuel pressure has always been 12-13lb recently dropped to 7lb, now 5-6lb.

I have an electronic westach gauge post filter. I suspected lift pump or filter getting plugged but, only 2k on new filter.



Today I put a snap-on mechanical gauge pre-filter and get 14-15lb.

OK, changed out filter, it looked brand new but, what the heck, this new ULSD and all.



Well I got 14-15lb pre filter. What gives? I have a grease gun hose for a snubber on the westach gauge, could this be deteriating and imploding resulting in a lower reading, I doubt it. What else? a bad sending unit?



The sending unit did start leaking, (real bad) where the wires come out the top. I took nuts and washers off the terminals and applyed a thin smear of ultra-black silicone to the washers and let cure for about 15 min , reassembled and no more leaks.



What do you guys think?? sending unit? I don't see what else it could be.



I hate seeing 5 lb, makes me nervous.

When I re-read your post, my eagle-like eyes revealed to me that your Westach gauge is post filter. I missed that the first time around. Sorry for the mis-reading, I meant no harm and was only trying to help with suggestions and moral support. I will now go and re-calibrate my eyeballs... lol...



Dave

 

[rweis]

I had a bad Westach electronic sender and they repaced it no questions.



Bob Weis

 

[RustyJC]

I've failed a number of Westach senders on the post-filter side. The diaphragm ruptures and the sender leaks around the terminals. When that happens, the readings go totally goofy. Replace the sender.



Rusty