6.5L Lack of Fuel problem.

[ff43sc]

I have had problems the past few monthes with my truck stalling/not getting fuel, In december I took it to a shop and they replaced the fuel filter and added racor bio treatment due to some water in the fuel.
Several weeks ago, still the filter would be 1/2 full of fuel again, took it to a shop and they found sender/tank to be rusted pretty bad and replaced the fuel tank/sending unit and main line from tank to pump. *seemed maybe it was sucking air before the pump, as the filter cannister would be half full when it would stall, I changed fuel filters yesterday and it was covered in a gray sludge, i took the filter assembly off and thoroughly cleaned it. With a new filter the truck ran fine, drove on highway ~20 miles and began snowplowing again. after about 30 min it did the same thing, stalled and occasionally after i bleed the filter it will idle with fuel at the bleeder but after a few minutes it loses fuel again and stalls. The lift pump was replaced yesterday am with a gm pump 2 days ago, I hooked a line to the line from the pump to a bucket and had an abundant flow of diesel. the pump seems to run constant and haven't noted it to cut out.

Could the filter have plugged again this soon? When I looked at the new filter it still looks completely clean. and no sign of particulates or dirty fuel in the cannister.

my guess is the sock in the tank or the filter may be clogging.

Any help would be appreciated. Already ran a fused power circuit to run the pump w/ignition to try to rule out an electrical problem. thanks.

[DmaxMaverick]

Could very well be an obstructed fuel pick up. Depending the replacement sender unit, it may have a relief inlet above the end (sock), and fuel level could indicate when you have an air issue (usually about 1/4 to 1/3). At any rate, if you got a bunch of "sludge" in the filter assy, a tank cleaning is in order. You could mess with it more, but in the end, the tank will likely still need cleaning. I would initially suspect the OPS, but since you ran a lead to the pump and still had the issue, the OPS is moot at this point. It may still be weak, but it won't be the entire problem. Drop the tank and get it over with.

[Robyn]

I agree with Maverick 100%

Drop the tank and completely clean it out. If the tank is real nasty inside, replace it and the pickup tube assembly.

The continued plugging of the filter and the possibility of getting some crap into the IP with the results being a ruined IP = $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$ :eek:

Get the entire system clean. Once the tank is clean, then purge the system using the lift pump and flush the lines out and into a can.
Reinstall a fresh filter and you should be good to go.

The shop probably did not completely clean the tank but simply did a half way job.

A large amount of water/crap in the tank can't be fixed with a jug of additive.

Depending on the model of your rig, many of the tanks are interchangable between gas and diesel trucks of the same year and model. Only the pickup/gauge sender is different.

You may also wish to question the dealer you buy your fuel at too.

I only use truck stops and usually I buy at the Card lock.

Reason being, if you foul up a few trucks the word gets around quickly that your selling mud and the truckers go elsewhere only after they burn your place down and break your back. :D

There are a lot of places that have very poor storage and even worse prefilters and lots of water and filth gets pumped into vehicles tanks.

Best of luck

Robyn

[ff43sc]

thanks for the replies max and Robyn, Tank is currently full, The tank and sending unit were replaced feb 07, in dec 07 same problem, took to diesel shop, they said water in fuel and replaced filter, running ok and again in feb 08 problem developed and shop thought it was sucking air *only happened around half or less of a tank, so they dropped tank and said they couldn't rule out pickup tube...so replaced sending unit assembly and and said main line was questionable(ohio salt...) so i had them replace line with factory line, now 2 weeks later same problem and i found the light gray sludge in the filter. Unless someone put something in my tank, not sure where the sludge would have come from.

Another question, does the cap need to be vented, i tried running the cap loose yesterday with no change. Going to a shop tonight to drop tank and clean everything again.
thanks

ff43sc

[daustin]

Sounds like there's crap in the tank and it's pumping that to the filter which gets clogged. I'd either lay purchase to 3-5 filters and change them every few days until that crap goes away or drop the tank and clean/scour it out.
IMO - I'd go the clean/scour route as you know it's clean then. IP's are several hundred dollars and i wouldn't take a chance on that. Do the clean route, install new filter and see what it does.
Don

[ff43sc]

Ok, we drained the tank after truck sat in heated garage all night, first 20-25 gal seemed clean and clear.. small bubbles visible in a clear hose on pump output. , we then dropped the tank, the last 5 gallons were extremely cloudy. and appears to have large amounts of water in it. completely emptied and cleaned the tank. and refilled.

2nd the fuel heater wasn't working at all. I don't remember seeing the water in fuel light ever come on when i turned the key on since i have owned it(7 years). Installed a new heater, water sensor, filter assembly(no one local had the parts so had to buy complete assembly. ) Now water in fuel diagnostic light comes on and goes off with key turned on initially so looks to be working now.

truck now running great, calling for snow tomorrow so that will be real test...thanks for all who replied. thedieselpage is an excellent tech source.