How old is too old for Diesel

[Infinite Monkeys]

Hi,

I'm getting ready to get a 1997 F350 Powerstroke in a day or so. The truck has been sitting for about 2 to 3 years. It currently has some issue that is preventing it from revving properly. I'm guessing this is due to a fuel delivery/pressure issue. I'll start by cleaning the FPR screen.

My question for now is that the truck has a half tank of diesel, about 2-3 years old, it does not have any preserver in it. Should I dump the tank and $50.00 along with it, or fill it to the top and mix good, new fuel with the old.

Thanks

[BigFuel]

Dump it. Gasoline falls apart in two months. Diesel will give you sometimes 3 more months then that but in the end what keeps the fuel thin and combustible evaporates in short order. Where are you? Was the truck in a field or in a driveway? I'd also suggest pulling the box off and removing the tanks from the top.

[NSTENGER]

I would dump it and give the tank a good cleaning. Bad fuel can cause so many problems, why chance it . . . .

[Infinite Monkeys]

The truck has been parked in a field. I will dump the fuel. A fresh start sounds like a really good idea. Taking the bed off will depend on if I can get a few buddies to come over. What does the bed weigh?

Why does a field or pavement make a difference?
I'm in northern, NM.
Thanks

[BigFuel]

A field would have all manner of plants growing into the underside of the truck holding moisture against the frame and body. Beds not _heavy_, more very awkward. Since it sat also look at all the rubber lines in the valley and under the truck. Get rid of the dry rot.

[Infinite Monkeys]

I'll start by getting rid of the drivability problems and then replace the fuel line dry rot.

From what I saw, it started fairly easy, after sitting for about 3 months, it did smoke some on start up and ran clean when warm.

It did not want to rev and only stumbled when the accelerator was pressed in.

It's got 225,000 miles and a new manual tranny. Should hopefully, last for at least that much more. Since I usually put only about 10,000 miles per year, this will be more truck than I'll ever need. It is 4X4 and crew cab.

Lots more questions coming up in the near future. I don't have any experience with diesel.
Thanks

[BigFuel]

No worries, ask a question and receive an answer. Be nice to that clutch for the first 100 miles or so.

[BigFuel]

Oh and run some Diesel Kleen (white) for a month or forever. Run a bottle of Bio Kleen too. No telling what is growing in your lines with it sitting.

[Infinite Monkeys]

Hope to get started on it in less then a week.
Thanks for the help.

[backwoodsboy]

Definitely dump the tank if it's been sitting half full for that length of time with no additive. If the tank had been full to the top, or an additive had been added it would be a different story (possibly).
Diesel doesn't go bad like gasoline. The cetane rating does degrade over time, but no-where near as quickly as octane. Emulsified water is the killer when it comes to diesel sitting for extended periods. Water means algae, and algae spells trouble for every component of your fuel system. I've burned diesel that was at least 7yrs old with no issues, but it was stored in a agricultural holding tank with the proper additives and had water drained off at regular intervals.
Drop the tank, and fill it with a few gallons of gasoline. This will act as a solvent and remove a good amount of sediment from the tank. Drain the gasoline and refill with fresh diesel, along with Seafoam Diesel Kleen, Stanadyne or another additive of your choice. Could also fill the fuel bowl with one of these additives, or ATF to purge the injectors.
Expect you replace your fuel filter and clean the FPR regularly (every 500-1000 miles) or so to start as you will have a lot of crud coming out of the fuel lines.