jmd025

I have good fuel pressure, always 15 + thanks to Airdog. If the truck sits for a while, it will lose prime and I will have to bump the starter a few times to get it primed back up. If I park nose downhill, it starts in a half revolution every time. I am sure its a pinhole in a return line, but I am having no luck finding it. Give me a nudge in the right direction guys! I hate when my truck sounds like a Powerstroke while trying to start ( you know, spins for 30 seconds then BAM!)

Oh yeah, when I shut the key off, the FP falls immediately to 0. Shouldn't it hold some pressure? It is mechanical plumbed direct no isolators.

fireram

I just posted a sticky on this.

I had a pinhole leak at the banjo fitting on the overflow valve on the VP44. It was small enough to let air in, but not fuel out.

I replaced it with new from dealer for around $100. it was rusted and looked like it was going to leak elsewhere eventually anyway, especially where it was clamped to the block behind the fuel filter.....

I took it off and plugged the hole with a bolt, then put air pressure to it in a pail of water and found the small hole..

I tried an inline check valve after my lift pump, it made it a little easier to start, but did not completely fix the problem so I kept looking.

my fuel pressure drops right after shut down as well. The Overflow valve in the VP44 has a small hole in it so it can NOT hole pressure, but will maintain a primed line, provided there are no air leaks somewhere...

Check the sticky, good luck....

Junk Man

My mechanical gauge immediately falls to 0, plumbed direct, AirDog, no banjo, 15-17 continual psi. Suspect leak at a fitting.

2002-5.9

A little pre-mature post here: I have the same issue of parking uphill and needing to bump the starter to re prime the system. I have located a extremely small leak where my Vulcan big line JIC fitting at the stock filter has a streak of wet fuel. Tightened 'er up and pressureized the tank at the cap with the shop air hose and rag. No more leak. I'll let you know tonight if it was the fix since the truck will be parked uphill all day. Fingers crossed...

jmd025

Well she's still doing it. I suspect something in the factory lines, as all of the supply lines are new. Heck, I may just have to replumb the WHOLE system. Sucks to be me.

collin_bucko

Is there possibly a leaking check valve somewhere letting the fuel flow back towards the tank. I had the same problem.

jmd025

only one check valve that I know of, and thats the one in the return line banjo on the VP. I pulled it out and cleaned it, and tested the spring pressure (by pushing it in, felt very firm). Maybe I should just replace it, I hear they are cheap.

You had the same problem, what did you do to fix it? Replace check valve?

2002-5.9

Well, that didn't work. I'm outta ideas other than adding a check valve on the pressure side of the pump. As far as the overflow on the VP return line there is a small bleed hole in the valve. Thats why you pressure will slowly drop to 0 when the pump is not running. I think the problem is more a fuel supply side issue.

dodge2001

i had the same issue about a yr and a half ago...i didn't have any leaks anywhere...i replaced the relief/return valve on the VP....still nothing...as long as i parked slightly down hill it would fire right up...

i ended up replace'n my VP....after that...no more problems...i don't want to jinx u...but....