lpccbis

Looking for help in a hurry.

Truck recently started deciding to not start on occation, but after 10 minutes or so of attempts will start like nothing is wrong. I suspect the lift pump which was replaced 3 years ago (as was the VP44). I ordered a check gauge from Gino's and hooked it up, started the truck and can get NO reading on the gauge.

Pics attached show the connection, the gauge face, a label on the top that states to trim the nub after install (can this have any affect on the reading? not trimmed yet) and an additional fitting supplied with the test gauge that I don't believe I need for my truck (1999)

Am I doing something wrong or is the pump or gauge not working, thought I would get some reading considering the truck is running???

Marine

If the truck starts but no reading then the gauge is not hooked up correctly.
If you sit in the truck with radio off, just bump the starter. Try and listen for the lift pump. Do you hear it? If it is in the tank of course you won't hear it. Next thing to try is to loosen the fuel filter lid. Get a second guy to bump the starter and see if it leaks from the canister. Of course don't do that on a hot engine.

Sent from my torqued out reuterbender

lpccbis

OK, never could get the schraeder valve to read, so hooked up to the clean side plug of the fuel filter.

At idle I'm running 28 PSI and driving I drop to 20-25 depending on throttle, just above 15 at WOT, so no starts cant be linked to that, unless she just quits periodically.

So will pressure this high damage the VP44??

Marine

From what I have read pressure that high will stop flow to the injectors. That is a huge fluctuation though; I would do another test.

Sent from my torqued out reuterbender

lpccbis

I'm leaving the gauge hooked up for a few days to see if the next "no start" shows pressure or not.

Unfortunately I never checked the pressure of this since the pumps were replaced so I have to assume the pressure was running this high for the past 3 years.

With my driving habits the pressure is generally 22 while driving, and 28 at idle.

Marine

I will look to see what max pressure should be; 28 is too high. Guys on here know and should chime in.

Sent from my torqued out reuterbender

lpccbis

Contacted FASS about the pressure, very helpful staff who informed me the pump is non adjustable and should only be putting out 18 PSI max. They also informed me that the shop that replaced my lift pump (and VP44) never returned the warranty card (nor was it provided to me to fill out and return) so rather than a 4 year warranty,, I'm only covered for a single year. . . . Mid October will be three years since the repair. Said the pump pressure increase is likely caused by a malfuntioning viton ball and they would send a new ball and spring to replace and hopefully fix.

After a day of driving 28-29 idle, 15 WOT

I'll plan to head back to the shop that originally performed the work and see if they will do anything about the warranty mix-up.

Since I have not been able to get the hard start to duplicate since installing the gauge, I cant eliminate the possibility that its not linked to the LP, but considering what I've been seeing it appears the VP44 diaphram may be weakened and unable to operate with that much pressure when hot

Marine

Glad you are on the way to a fix!