Old Fuel - Rough on the Injection Pump?

[MaximumBob]

Originally posted on CUCV Forum, but nobody saw it because it was on the tail end of an old post about "Cheap IP Rebuilds".

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Quick Question - My M1008 doesn't look like it has been run in a while - the date on the fuel filter is 7/2005. A buddy of mine told me that the fuel in the Injection Pump will gel and when the motor is fired, the gel inside the IP will trash the pump. What my buddy described sounds consistent with the [IP Rebuilding] on the CUCV Forum. Has anyone else heard of this?

Also, again according to my buddy, the cure is to pull the injectors and flush the old fuel out of the IP by cranking the engine - he's even got a reciepe for some diesel-fuel-based cleaner that you're supposed to suck through the IP (by cranking the engine). Supposedly, by pulling the injectors and running fuel through the [now open] injector lines, the pressure inside the IP is reduced and it won't hurt it to flush out the gel.

This all sound: (1) reasonable? and (2) necessary?

Thanks,

Bob

Jacksonville, FL

 

[cranetruck]

What does the fuel look like in the fuel tank? If it hasn't "jelled", you should be able to turn the engine over without a problem, most of us do and our truckes have been sitting for a lot longer than two years...guess ignorance is bliss...
But do change all filters before trying to fire it.

 

[Bill W]

I have spent 26 years cleaning fuel on Motor Yachts and have yet to see diesel gell from old age. The oldest ( documented through the boats log book ) fuel I've seen on a yacht that still burned was 7 years old, it had turned a day glo yellow in color but still burned, this is not good for the injectors but I could not convice the know it all owner of the boat who did not want to part with 700gal fuel! My 5 ton has 50 gals of old fuel in it, I plan on draining & cleaning the tank,changing filters, putting in new fuel with some "Diesel Kleen" additive ( made by Power Service) and let her run.

 

[devilman96]

7 of 05 really isnt that old... 7 of 95 might get intresting... I wouldnt worry bout it!

 

[MaximumBob]

Thanks guys - I think I'll drain the tank and put some fresh fuel in - other then that, I won't pull the injectors - looks like a big job - from what I understand the intake manifold has to come off, and of course - all the injector piping. My 15-year-old son is pretty excited about cranking this bad boy up, so skipping this [unnecessary] step will speed things up considerably!

 

[MaximumBob]

RED Fuel? So I drained the tank this weekend. I started siphoning from the filler neck and noticed that there was fuel leaking form the top of the tank where the rubber filler hose attached. Figured if I was going to have to tighten the hose clamp anyway, why not pull off the hose so I could go right into the top of the tank with my little hand pump.

Got the hose off without too much trouble (hint - works best if the vehicle is up on jack stands and the rear driver's side wheel is removed). Next I lowered the rear drivers side off the jack stand so the vehicle was almost sitting on the rear driver's side brake drum. The fuel was now all in the corner of the tank.

Only got about 2.25 gallons out - tank was almost empty. Three significant things:

1) Included in the 2.25 gallons was 0.5 gallons of water - guessing that my 1985 CUCV M1008 is NOT one of those hydrogen converting hybrids, I'm glad I got the water out.

2) Fuel seemed reasonably clear - so hopefully no problems in the fuel system other than water.

3) The fuel is RED - my guess is that all government diesel is red because they don't pay transportation taxes. I'm making this part up - anyone know the real reason?

We refilled the tank with 20 gallons of very fresh diesel - could still be a while before we crank the engine and a full tank will cut down on the condensation in the tank.

Any comments on the RED fuel would be appreciated. Also, any specific additives I should throw in the tank to help clean the pump and injectors?

 

[wreckerman893]

Red fuel is "off road diesel". That is fuel that is sold without road taxes added to it for farm and other non-highway use. Sounds like the previous owner was trying to save a few bucks on fuel costs. If you get caught running off road fuel on the highway you can be fined. Chances of getting caught are slim unless you go through weigh stations where they can pull random samples or someone rats you out to the "man".
The fuel we used when I was on active duty was the same color as commercial fuel.
There is also the chance that someone put automatic transmission fluid in the tank to "clean" the injectors.
Just my .