I've got a manual 85 F250 6.9L that has been my daily driver for the past 2 months. Up until now, no running problems (glow plugs are bad, but working on getting the pushbutton setup). This morning it was a little harder to start than normal. It took more cranking time to catch, started then quit, but when I got it started the second time and kept on the gas for a few seconds it lined out and I was able to take my foot off the gas and let it idle.

On the way to work I shifted into neutral on my way to a stop sign and the truck stalled. I pulled off to the side and managed to get it going, but it stalled as soon as I started (just like that morning). Started it again and kept my foot on the gas for a full minute or so and it seemed to be fine again (a little rough and shaky during the idle, but not stalling). Not 100 yards away it stalled again but this time my attempts at restarting were cut short due to dead batteries.

I had noticed yesterday that the truck idled a little rough at a stoplight but didn't have any problems. It almost sounds like I'm running the fuel tank dry but I've got plenty diesel in the tanks. I've read that having low oil may be causing not enough fuel to get in for combustion. The truck burns oil but I topped it off about 500 miles ago. I'll check the oil level when I get back out to it, but was wondering if anybody knew of other potential reasons the truck stalls at idle. Would increasing the idle speed help at least temporarily to get it home. I'd much rather work on it in my driveway than where it is truck is parked in a seedy part of downtown, plus I locked the keys in it... rough morning).

Some other background information about the truck: bought it from a farmer who used it as a daily driver until he got a new truck ~1 year ago. So it sat out under a tree with limited use for 10 months until I bought it. Also read that gunked up fuel could be an issue, but after I bought it I replaced the air filter, oil filter and fuel filter, none of which were in too bad shape. None of the gauges on the truck work except the odometer and spedometer. Fuel gauge works intermittently on one of the tanks but is nowhere near accurate. Truck has diesel in it (only 100 miles on the tank I'm running, typically gets at least 225). Someday I'll get around to fixing them, but have been tied up with higher priority projects so far.

 

did you change out the water seperator also? i got a 87 6.9 from bridge city about a year and a half ago and it ran great for the first week. then no go, i had a small pinhole in the fuel line at the lift pump.... just a thought, but mine apperantly spent some time on bolivar

 

Does it sound like it has a lope while its idleing. Before u go to check it out stop and get a couple cans of seafoam from napa. Fill the fuel filter with it. Set the idle up it cant hurt. Just watch the clutch.
How many miles does the truck have?

 

It's a fuel issue.

The first thing I would do is get the Batteries charged up.

The second thing would be a fuel flow / pressure test at the Schrader Valve.
You should get 1/3 pint in 10 seconds while cranking and like 6 lbs of pressure.

Then it depends on what the results are from the flow test.

The things it could be.

• Pickup Tube in the Fuel tank, try a different tank if you have two.
• Air leaks in the suction side of the fuel system. (Before Lift Pump)
  • Cracked or Leaking Fuel Supply lines allowing air intrusion.
  • Water Separator allowing air Intrusion
• The lift Pump
• Bad Injector Pump.

-Enjoy
fh : )_~

 

Water seperator (drivers side inner fender on firewall) gets my vote.

 

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I second this I would pour 5 gallons in each tank first though.

 

Didn't expect all the responses before I got back from work (that's a good thing I guess) so I'll try to respond to the questions above.

First, oil level is good, about the same level as when I had topped it off.

Haven't drained the water separator since I got it, the light never came on. That's got me thinking that the light might not be functioning. When I turn the key only the check engine light comes on, should the water light come on as well (glow plug light has been disconnected for use with manual pushbutton)? I'll try draining that first then trying to crank it once the batteries get charged.

Got the truck from Port Acres so there's a chance it was in some water during Ike and Rita.

If I don't give it some gas at idle, it'll lope once or twice then die on me.

Truck has ~150,000 miles (or maybe 250,000 but P.O. said it was only 150).

If my water separator was full of water and got some injected with the fuel, what kind of damage would that cause? I do remember the engine changing tone while cranking just before it normally would turn over (lack of working glow plugs keeps me using ether to start a cold engine, number of times engine turns over before catching is almost constant depending on spraying ether at the end of the air intake hose or disconnecting it and spraying at the filter inlet). It got significantly more sluggish but that might have just been the batteries dying on me. But does water in the fuel explain the stalling or is it more of a question if the separator has an air leak?

Question on changing the idle speed just to get it home. Since it won't run for long at idle, can I adjust it prior to starting with the engine off? How many turns in which direction would you recommend?

 

Also, how do you test fuel flow and pressure via the schrader valve? Is this something I can do or is it a take it to a shop kind of thing? To be honest I don't know where the schrader valve is.

 

The water separator light should come on with the ignition on.

You can pull your fuel filter and dump it in something clear (I use a soda bottle) and let it settle a bit, water will separate.

It could be water, water left in the system will destroy it, you need to ensure you get all water out if you have water in the system.

-Enjoy
fh : )_~

 

The schrader valve is on the fuel filter head, it looks like a tire valve stem.

Pull the valve core (like a tire), then hold a soda bottle or the like up to the stem and turn the motor for 10 seconds ...

To pressure test you need a gauge you can hook to the schrader valve.

-Enjoy
fh : )_~

 

hey J, port acres didnt get any water as far as i know,But, i also dont know how far out the levee's go for sure either. I want to say that it was ok, but then again, that may have been the path the water went in to labelle hamshire and fannett too. mine was left in BC durring the storm, water up over the shifter boot, when we went to get it, it cranked right up, got it here on a trailer and changed all fluids

 

There shouldn't be any water in your system the filter should catch it and stop the flow of fuel before water ever gets to the IP.
If your waterseperator has not been bypassed (a lot of them are) and you drain it you will need to put a bolt in the drain hose and clamp it. They nearly always leak after draining causing hard to no starts.
I have owned several of these and have never bought one that sat for a few months that I didn't have to put a returnline kit in nearly immediately. I guess the hard orings just leak when you start running fuel through them again. that is my personal experiance.
Even with either some of these will not fire without fuel too I don't know why I do know either is not near what it was 20 years ago.
If you are using either disable your glow plugs completely you don't one accidently coming on with either in the cylinder things can get expensive quick.
If it sat for awhile I would change the filter filling it comepletly with howes, dieselkleen, seafoam or other good additive that is a cleaner and lubricant. I would also run a double dose or tripple dose in the first tanks. This helps lube and clean the ip and injectors and the govenor sometimes gets sticky from setting especially in a humid climate.
To disable your glow plugs just pull the purple wire off your relay.
Good luck.

 

Update -

Got it cranked and running again after speeding up the idle. It didn't give me any problems until about 2 weeks ago. I got back from a week away for work and started her up and when I parked and shut it down the engine kept running for a few seconds longer than usual. It was hard to start again, but I got it home and when I shut it down in the driveway it kept running for about 15 seconds. After that it was near impossible to start up again.

I went out and got a new fuel filter and a few cans of seafoam, filled the filter and put one in the tank. It still wouldn't start and I eventually ran the battery down. So today I went out and filled 5 gallons into the tank and charged the battery. It took a while but she started up and ran fine. I was even able to take the idle back down to where it was before. I can definitely tell a difference in the pedal response. I was a little curious as to why I did not see a lot of white smoke come out the exhaust when running with seafoam. I've seen some videos online and I expected at least a little bit of smoke, but nothing - clear exhaust. Wondering if anybody has any thoughts on that.

 

i know when i ran mine the first time i got just a little smoke, next time i got it up to op. temp, then filled the filter with foam and let it run for about a minute or 2. killed it and let it set for a few more and got a bit more smoke. supposevely when it sits it is able to eat/dissolve the carbon build up.

 

With the return lines, I would say run the engine about 30 seconds, then shut it off if you want your cleaner to be in the IP.

A double or tripple dose of injection system cleaner in the next two tanks of fuel might do you a world of good since it sat for a good while.

If the stock water seperator is still installed, that is part of your problem unless you have the drain line blocked off.
Mine was leaking around the pull ring, so even blocking off the drain line was still letting it suck some air.

The fuel line pickups in the tanks are famous for cracking or even breaking off.
That can let you run out of fuel with over 1/2 tank of fuel, depending on where it cracks at.

Return lines and O rings would probably be a good idea, if they are not the problem now they will be soon.

So your problem might be a combination of things.

Your engine will run on a variety of fuels.
Some are not really a good idea, some cause other problems and some are just like diesel fuel in the way it runs.

The list includes but is not limited to,
Automatic transmission fluid
Kerosene
Jet fuel
Hydraulic fluid
Motor oil
Vegtable oil
Peanut oil