Hey guys my fuel pressure usually sits @ about 10 psi. This afternoon it went through the roof. At first it crept up to 15psi this has happened before once or twice-no big deal. I turned the truck off for about a 1/2 hour, when I started it up again the needle was maxed out at 30 psi. I had a 5 mile drive back to work, while driving it went down to about 25 psi. I should mention that when I restarted it after the break it had a hard time starting, it cranked and cranked and finally turned. Lift Pump again? Checked codes-nothing.

What do you think...thanks in advance

Tom

 

some kind of restriction downstream?

 

I would say that you need a pressure measurement to confirm your on board guage. You may have a bad sender or ground causing wacky readings. If the pressures are really that high then you will be looking at a lift pump.

 

just saw this site with way more info on the VP44 than I'll
ever need.

http://dodgeram.org/tech/dsl/ISB/Vp44.htm

including...
"The second solenoid in the pump is used to meter fuel to the injectors. The solenoid opens the fuel metering valve to allow fuel from the supply pump to flow into the pumping chamber. Once the pumping chamber is charged with fuel, the solenoid valve closes. This traps the fuel in the chamber and allows injection pressure to build..."

Sounds like if this part was having sealing issues it could back-pressure
the line from the lift pump. (?)

(this is where the experts should chime in...)

 

thanks for that link. that's the best info i've read on the 44 since i've been a member. the description of operation does not mention any relationship between the amount of fuel pressure from the lift pump and the all wise advise that this is the magic number that decides the life of the 44. all return fuel appears to travel other routes. if i read this correctly, all the internal pumps are the most likely to fail along with the electronics that drive the 44. only read it twice so i may have missed something.

 

thanks for the insight guys, Im showing 1693 codes today, Im gonna have it read hopefully, tomorrow

 

Is the fuel pressure gauge electric or mechanical?

The factory lift pump, even dead headed, won't go much over 20psi.

There is a big big chance your gauge, or POSSIBLY your IP is FUBAR, or (')(') .


Merrick

 

It's not uncommon for the lift pump to loose it's mind and the gauge read high for no apparent reason. Happened to me. What happens is the ball and spring inside the lift pump comes unseated and the pressure goes up - but only for A SHORT time period. What then happens is the lift pump will head south. Mine lasted for about a year until I didn't like the pressure readings and I changed it out. I kept the old one for a spare.