Diesel runs rough once warm?

[~Joe~]

Tractor: Iseki TU2100F - 24hp 3cyl

The problem started yesterday afternoon after several hours of use. It started runing very rough, was about dark so I parked it. Today, started right up and ran fine for first 20min and then went back to runing rough, no power. Checked the basics and all seems ok. I figure if it were the fuel filter or air in the line it would do it on startup as well.

Possible glow plug issue?
Could the injection pump cause this?
New to diesel so any advice would be aprreciated.

Thanks.

 

[jimmer2880]

what are the temps like? If it's near or below freezing, it could be fuel problems.

With Diesel, many will run fuel treatment year round to help with the gelling issues.

 

[~Joe~]

what are the temps like? If it's near or below freezing, it could be fuel problems.

With Diesel, many will run fuel treatment year round to help with the gelling issues.

60 today, fresh fuel

 

[Treemonkey1000]

The glow plugs aren't involved once it is started so that isn't the problem. Your injector pump might be worn and once it has warmed up a bit you aren't getting the pressure to the injectors. It is doubtful that if you had crud in the fuel tank that would take 20 minutes before that caused problems. How long has it been since the air and fuel filters have been changed? Is the coolant level ok? Does the tractor smell hot like your coolant isn't doing it's job? Basically are the oil pressure and water temp gauges working and showing you normal levels? How many hours on the machine?

 

[brandoro]

If the fuel filter is plugging up it will run okay at idle and until you put some load on it and start trying to draw more fuel through the filter. I had a fuel filter plug up on a diesel truck I had, it still ran okay but way down on power. It gradually got worse until I was starting to wonder if it would get me home or not. Finally made it, a fresh filter got it back to normal.

 

[George2615]

Since he's in NC I don't think he has a freezing problem. Sounds more like contaminated fuel. Maybe got some water in the diesel. Another possibility would be a plugged air filter (runs fine on startup then needs more air once warmed up). If you were running it in a dusty environment that would clog the air filter.

 

[Egon]

Sounds more like contaminated fuel. Maybe got some water in the diese

That surely sounds like an item that should be checked out.

 

[~Joe~]

If it were fuel it would do the same on startup correct?

 

[Diamondpilot]

Fresh fuel means nothing. Both times I have had fuel issues it was just after fueling up. PULL the Fuel Filter and take a look.

Chris

 

[Chilly807]

If it were fuel it would do the same on startup correct?

If it were fuel quality, yes. Filter problems (fuel quantity) take longer to show up, since the engine uses very little fuel at idle or unloaded. Once it has burned what was in the filter, it has to draw more fuel through the filter, ergo the problem.

If you haven't changed the fuel filter recently, it's a good place to start.

Chilly

 

[slan]

I agree, its probably the filter being plugged up or you are sucking air somewhere.
Do you have a fuel bowl that you can see into? after it starts to run rough check to ensure the bowl is full.
Is there a bleed valve somewhere that is not closed tight, thats exactly how mine reacted when the bleed valve backed off a bit.

 

[dboacres]

Had same thing few years ago. Was bad fuel which dirtied the filter. Started right up ran for a while then would choke. Filter!

 

[Jerry/MT]

Tractor: Iseki TU2100F - 24hp 3cyl

The problem started yesterday afternoon after several hours of use. It started runing very rough, was about dark so I parked it. Today, started right up and ran fine for first 20min and then went back to runing rough, no power. Checked the basics and all seems ok. I figure if it were the fuel filter or air in the line it would do it on startup as well.

Possible glow plug issue?
Could the injection pump cause this?
New to diesel so any advice would be aprreciated.

Thanks.

A diesel in reasonable mechanical condition needs fuel, air and a good battery and starter to start and run. It usually needs a starting aid in cold weather to start.
When is the last time you changed the fuel filter? Do you have adequate fuel flow from the fuel tank through to the filter(s) and the injector pump? I'd suspect fuel delivery to be a problem in your case. Check the screen in the tank for crud, change the filter(s) if they haven't been changed for a while. Make sure that your air filters are clean and tighten up the fuel line fittings. Some flters ahave a water drain at the bottom so you can drain the water out of the filter bottom. If you have one drain some fuel into a container and see if there is any water in it.

 

[south branch]

How about a plugged vent cap on your fuel tank. It would run fine till it pulled enough fuel to create a vacuum on the tank, then it would be starved for fuel. Next time it starts to run rough open the fuel tank filler cap and see if the problem goes away.

 

[dqdave1]

Check fuel filter; then check air filter; check all fittings on fuel lines; they may leak (suck air) after getting warm and expanding.

 

[Bear Foot Farm]

When mine did the same thing, it turned out to be the mesh filter inside the tank was clogged.
It would run great for as long as it took to drain what was in the fuel lines, and then run rough and finally cut off.

 

[milkman]

Another vote for fuel filter. my fuel filter problem has virtually disappeared since I started using a Mr Funnel, paid for itself many times over.

 

[~Joe~]

The inlet fitting on the fuel filter had come loose allowing air to enter the system. A little permatex gasket sealer on the fitting, new filter, & fressh fuel and now she purrs nice and smooth. :thumbsup:

Thanks folks.

 

[JnDPgh]

I had a similar issue with my B8200 where it would run fine for 20-30 minutes then begin to run rough and stall. The reason for my issue was that a small crack in one of the rubber lines that lead from the fuel tank down to the injectors. Once the fuel in the lines had been used it began to suck air through that crack leading the engine to run rough and stall. Replacing that rubber line solved my issue.

 

[PILOON]

Plugged breather in fuel cap.---run with cap off or loose.
Trash in tank screen.----blow air back into tank
Gelled fuel filter (winter)---- add 911 (use additives all winter is best prevention)
Air leaks in any line.----fix or replace
Dirty filter.----change
Water contamination.-----drain and in future use suitable filter when filling

Metal tanks partially filled can sweat in proper conditions and allow some water to collect.

Also there is a difference between summer and winter fuel, summer gells faster in winter.

Your observations can fit most of the above causes, start with the easiest and eliminate.