Old Fuel in Diesel Tractor

   / Old Fuel in Diesel Tractor #31  
You have never watched Hank and Wiley on the Hamiltonville Farms YouTube channel start and operate diesels that have been sitting for 10+ years using just the fuel left in the tank have you?

Nope, nor am I interested. Seen plenty of people start up diesel engines with old fuel that ran 1 time. Then afterwards had to tear into the fuel system to repair.

Diesel bacterial growth is very difficult to control. Even with fuel treatments.
   / Old Fuel in Diesel Tractor #32  
With the age of the diesel, drain the tank. There may be a buildup of crud at the tank outlet. If you can't drain the fuel you'll have to address that problem first. Replace the fuel with fresh fuel. Replace the fuel filter. Bleed the air out of the fuel lines then give it another try.
This ^^^ is the problem with my 45 year old MF, crud and rust in the metal tank blocking the tank outlet. My suggestion if you suspect this, close the valve just below the tank and then disconnect the downstream fuel line. Then open the valve to see if you have free fuel flow coming from the tank. If not, a puff of air up into the tank from the shutoff valve can temporarily remove the clog. I’m in the process of replacing my tank to put an end to this issue.
   / Old Fuel in Diesel Tractor #33  
You can often solve rust in a metal tank by tying a good heavy string like baler twine around an old horse shoe magnet and putting in down on the bottom of the tank. As fuel moves round any rust it will attach. From time to time pull it up and clean it off and reinstall.

Do this after you have opened to fitting at the bottom of the tank and flushed it a time or two to get as much out as possible.
   / Old Fuel in Diesel Tractor
  • Thread Starter
If it sat for that long would it be more likely 'gel' up? As in the paraffins in the fuel crystallize? Especially in cold weather?

I'm just spit-ballin' here but, what about maybe adding a butt-load of a GOOD additive that might break that junk up?
I need to read up on additives, don't know if they will repair.
   / Old Fuel in Diesel Tractor
  • Thread Starter
I've started diesel engines that had fuel in them so long it smelled like paint thinner! I never drained that old fuel, just added new. Just lucky maybe.

As described in this thread, drain any fuel you can from the tank, install new fuel filter and fuel, check for air leaks, use your manual primer pump, crack open fuel line at injectors to eliminate all air. If using your starter be sure to not over heat it. Crank the engine for 20-30 seconds a few times then wait for a couple of minutes to keep starter motor cool, or you'll have another problem to fix.
Will do.
   / Old Fuel in Diesel Tractor
  • Thread Starter
The symptoms you describe imply a fuel restriction. These can be caused by debris in the fuel tank, condensed water freezing in cold ambient temperatures, use of summer blended fuel in cold ambient temperatures (waxes precipitating out of fuel), bacterial sludge in the tank blocking the outlet strainer or various downstream components, non-functioning left pump (if installed) etc
Start at the fuel inlet line to the injection pump and using a container to catch the fuel, open the tank valve. Do you have a gush of fuel or is the flow intermittent or just dribbling? If it is not a gush, then work your way back to the tank outlet until you get full fuel flow and then you have found where the blockage is. If you have a lift pump, make sure it is working to supply fuel. Some have a screen in them that can clog, or they can fail.

Water in the fuel occurs from condensation (assuming you don't leave the fuel cap off) and is the start of bacterial sludge as the microbes live in the fuel/water interface. No Water, n bacterial sludge. You can't eliminate condensation but you can minimize it by keeping the fuel tank full of fuel between uses. Drain your fuel filter regularly and look for water in the drainage. If you have a water separator, drain that also. Treat you fuel as it helps the water accrete on the filter and then slide down toward the bottom to be drained.
If you have a solenoid on the injection pump (IP), Make sure it is functioning properly. There are usually two solenoids; an opening solenoid and a holding solenoid. They are both on when starting and the opening solenoid shuts off in the key switch run position.

Systematically go through the fuel delivery system and you'll find the problem.

Hope this helps.
Thanks, good info. No shutoff valve, lift pump, or water separator. Gravity flow to the filter.
   / Old Fuel in Diesel Tractor #37  
You may need to crack each injector feed line to get the air out. Google how to do that. Only back off the nut a 1/4 turn or so. The idea is to get all trapped air out of the lines and through the injection pump up to the injectors. There will be bubbly diesel and then solid stream. It might help to have a second person to bump the starter for this, depending on layout.
I made a jumper to bleed down my lines using a momentary contact switch (button that is on when pressed, off when you let go) and alligator clips. Hooked one side to where the battery cable connects to the starter, the other side to the starter solenoid. Make sure it is in neutral, brake set. This allows you to operate the starter while standing next to the injection system.
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   / Old Fuel in Diesel Tractor #38  
I need to read up on additives, don't know if they will repair.

SEAFOAM. This was it's original purpose. And it works better for diesel vs. gas. And people rave about how good it works in gas engines. Go figure.
   / Old Fuel in Diesel Tractor #40  
Thanks, good info. No shutoff valve, lift pump, or water separator. Gravity flow to the filter.
You have a lift pump. I see it in the picture. It's what you called a "primer". Is there a water separator up stream of it?