93 fuel manger?

[ghitch75]

do they have a check valve in them?.....i have had my 93 1 ton parked ass end down hill for the past couple weeks(it usually set ass end up) .....if it sets for more than 2 days it starts then rev's and dies.....pop hood open bleeder on filter big shot of air then fuel.....i raised the bed and checked the fuel lines for leaks.....all are dry and tight....


need some thoughts from the :grouphug:

 

[farmboy56]

Take your lift pump fuse out (on passenger side firewall behind black cover) and while the truck is turned off, ground out the fuse and you should hear the lift pump running, then open up your bleeder valve and let all the air out. Do a couple of times til you receive only fuel coming out. Also make sure your water valve is completly closed and not leaking out for any reason. It sounds like its a symptom of the water valve being open because mine will do the same thing when I crack it open.

93 6.5td = mechanical injection. Look at my mods and simply turning up that pump, adding 10psi of boost and 40hp marine injectors will blow your mind. I can hang tight with the cummins and beat newer gasser rigs on the street. And still get the same fuel mileage. I have been running my rig like this for 25k miles and havn't had any problems.

 

[ghitch75]

LP is runnin' fine...got 12psi @ idle and 4psi @WOT.....just want hold fuel with ass end down parked for a couple days...

 

[mattthebrat]

I am not sure about a check valve in the FM, but IIRC there was a check valve in the LP, I would think they both should have a check valve.

Sure sounds like fuel is draining back somewhere.

 

[Matt Bachand]

Filter manager sits alot higher than LP and fuel tank anyhow, so if it were to leak it were to leak back when truck is level too I would think?

I know you can't blow backwards through a factory LP.

You can buy a fitting w/check valve built into it, and put that inline feeding the fltr manager, or after the LP whichever is easier for you. Cheap.

 

[540s10]

you have a leak somewhere in the fuel system, thats the only way air can get into the lines.

 

[ghitch75]

i raised the bed again yesterday and checked every line and fittin'.....dryer than a popcorn fart!!!....took a flash light and checked under the intake and down the firewall....all dry...

as i said it only does it when it's parked ass end down....when it's nose down no problem....that is when i think i would see a fuel leak....i'll pull the LP and see if i can blow back though it.....i would guess that the time it takes to get the air out of the FM that it about half full or half empty dependin' how you look at it!!!...lol

 

[Missy Good Wench]

The most likely issue is that the check valve in the lift pump is leaking back or you have a small air leak around the throttle shaft in the IP that is allowing a small amount of air to enter the system and allow that thing to drain back.

This is not uncommon when these critters get a lot of time on the clock.

Many times the fuel can't leak out but after things cools off, air can seep back in, especially when the truck is parked tail end down.

The addition of a small check valve just before the fuel manager will usually stop this.

The issue is that this check is a bandaid for the real problem.

Probably your IP is leaking air back into the system when parked.

The fuel managers do not have a check valve in them.

MGW

 

[ghitch75]

The most likely issue is that the check valve in the lift pump is leaking back or you have a small air leak around the throttle shaft in the IP that is allowing a small amount of air to enter the system and allow that thing to drain back.

This is not uncommon when these critters get a lot of time on the clock.

Many times the fuel can't leak out but after things cools off, air can seep back in, especially when the truck is parked tail end down.

The addition of a small check valve just before the fuel manager will usually stop this.

The issue is that this check is a bandaid for the real problem.

Probably your IP is leaking air back into the system when parked.

The fuel managers do not have a check valve in them.

MGW

i checked the shaft....engine has around 185,000 on it and the IP has around 50,000 on it.....i robbed it from a jasper rebuild when the PO blew a heater hose and drove it 25 miles and it's locked up tighter than a tick......won't there be fuel leakin' from it when it was runnin'?....shaft and seal are dry and no slop....i had a LP go bad from Heath on the burb and Bill said the check valve was bad and it wouldn't pump at all.....this 1 pumps fine(see above)....i'll pull the LP and check the check....

btw the tank and sender are a little over 2 years old

these problems like this make you:mad2:....lol

 

[Turbine Doc]

Disconnect the outlet of the lift pump and plug the fuel return to tank line, pull vacuum with mity vac or similar on the line for outlet of the lift, if you are losing vac you'll know the leak is somewhere in that circuit, maybe leaking on the fuel return circuit, which would leak air but not fuel in any great quantity to notice.

For the tank side pressurize the tank with 3-4 psi air and "soap solution test" the lines they should bubble up where a leak would be present, maybe even air press test vs vac test on IP supply side, but I've seen cracks in rubber fuel lines before that "seal" under pressure, but open up without it,

So vac would be better there as that duplicates exactly what the lift & IP are doing when pulling fuel from the tank, you should be able to pull & hold a vac on the system if there are no leaks present in the lines, but capping off all outlets pulling a vac on the fuel tank side of the system unless you had a electric vac pump could be a long process, so easier to pressurize and "soap test" that side of the system