Fuel Pressure

[RSWORDS]

Just got the fuel pressure gauge hooked up. Used the banjo bolt on the top of the fuel filter housing. Well I Have 6psi... That is at Idle, cruise, and WOT. 6psi. Does not move at all. Any ideas? Also I have developed a slow drip, like one drop every 20 seconds, it's not coming from the new hook up but I think the water in fuel sending unit on the bottom of the fuel filter. I hit the drain and then it stayed open till I pulled it out. Can these be fixed or cleaned or just replaced?

[cummins king]

seems a bit low

when i had stock fuel system on, i was running 8 or 9 psi at idle, 12ish for cruzin, and wide open i could get 15psi, and if i held it there it would go down to 1psi

[PToombs]

ck, that sounds like a lot for a stock system.

RSW, That is plenty of pressure for a stock truck. Strange it doesn't fluctuate at all, are you sure the guage is good? No less than 3-4 at WOT is good.
On the drip, pull the WIF sensor, clean it good with brake cleaner or some such. Open the drain and blow thru too. Blow off with air, should be good to go.

[cummins king]

gauge dont lie it was more like a 14psi wide open

[Ace]

All else being equal, I think not fluctuating is probably a good thing. That means the fuel system, including the pickup, lines, filter and pump are supplying the engine demands under all conditions.

I've seen four distinctly different stages of this phenomenon as my fuel mods progressed. I thought I found the last bottleneck at stageIII, but just last weekend proved myself wrong again.

1) Stock system. Average 6psi, but all over the place depending on throttle position, filter condition, even ambient temperature - not good.

2) Piston pump. Much better, but still pulling down 6-8psi at WOT, with just pump mods and stock IC injectors.

3) Installed BIG filter. Noticeable improvement. Only pulled down 2-3psi at WOT.

4) BC847 Fuel Pickup Mod. Had the tank out last weekend to do some mods behind the frame there for my Torsion Links (more on that later) and decided to do the fuel pickup mod developed by BC847 while I was at it. That pickup sqeezes down to a pretty small orifice in there, no doubt. Now running the piston pump and big filter through an optimized tank pickup it runs right around 15psi ALL THE TIME - except as it overruns up to 16-17psi cruising downhill or sitting at idle.

I'll upgrade that main feed line to 3/8" if ever need be, but for now, the FP gauge tells me that won't be necessary.