engine falling flat

[AgT250]

I'm new on here - 1st post. I have a 2003 T250 with 2500 hours that has been an absolute workhorse on our farm for the 4 years I've owned it. Other than a blocked intake in the fuel tank a couple of years ago or so, it has been virtually trouble free - until today. I was heading out to the woods to load logs and the engine stumbled and fell from 1500rpm's down to 750. I pulled the throttle to idle and the RPMs came back up to 1020 like normal. I opened it up to full throttle and it went right to 2350 for a few seconds (accompanied by white/blue smoke) and then stumbled all the way down to 750 to 900 RPMs until I closed the throttle and it returned to 1020 again. Any moderate load causes the missing-stumbling in all RPM's. I finally made it back to the machine shed by letting it "catch up to itself" several times. I checked the primer bulb and it wasn't collapsed - even at high RPMs so I figure the intake/ backflow valve in the tank wasn't clogged and also I can hear fuel in the return line to the tank when I squeeze the primer bulb. Diesel fuel flowed out of the filter drain with and didn't notice any water. Outside temps were in the mid 30's and I use diesel fuel conditioner without fail - even in the summer. All temps and oil pressure normal and there are no "alerts" on the monitor. No odd noises from engine or turbo. Any ideas for troubleshooting appreciated.

 

[mrdeere1959]

try changing the filer, or run the primer bulb up so you can pump it when it starts to die down

 

[AgT250]

try changing the filer, or run the primer bulb up so you can pump it when it starts to die down

I finally figured things out earlier, but you are correct on the filter. The primer bulb was hard to squeeze and didn't affect engine speed much at all. Started to think that although clean fuel ran out of the filter, the flow wasn't that great-even with help from the primer bulb so I went ahead and took the filter off - even though it was fairly new. Unbelievable that the machine ran at all. I have recently changed diesel suppliers and they have bio-diesel. Must have cleaned the whole fuel system out by judging the filter. Runs like a striped ape again with a new NAPA Gold filter. Will have another on hand just in case. Appreciate your reply.

 

[Ironmule]

I finally figured things out earlier, but you are correct on the filter. The primer bulb was hard to squeeze and didn't affect engine speed much at all. Started to think that although clean fuel ran out of the filter, the flow wasn't that great-even with help from the primer bulb so I went ahead and took the filter off - even though it was fairly new. Unbelievable that the machine ran at all. I have recently changed diesel suppliers and they have bio-diesel. Must have cleaned the whole fuel system out by judging the filter. Runs like a striped ape again with a new NAPA Gold filter. Will have another on hand just in case. Appreciate your reply.

My t250 sucks the bulb flat after running an hour or so. How do I clean out the check valve in the tank. It looks like alot of fun since you can't see the tank.

 

[Tazza]

My t250 sucks the bulb flat after running an hour or so. How do I clean out the check valve in the tank. It looks like alot of fun since you can't see the tank.

Lift the cab, its behind the drive pump. Access won't be great, but you can get in there. Just make sure you get the pickup line, not the return one. Best to fight re-installing one line than two, been there before now....

 

[AgT250]

Lift the cab, its behind the drive pump. Access won't be great, but you can get in there. Just make sure you get the pickup line, not the return one. Best to fight re-installing one line than two, been there before now....

Luckily, someone on another site cautioned me not to use compressed air to clear the pickup line. It will blow the end off of the fuel pickup. There are some good archives on this site from 2 or 3 years back on how to do this this, too.

 

[Tazza]

Luckily, someone on another site cautioned me not to use compressed air to clear the pickup line. It will blow the end off of the fuel pickup. There are some good archives on this site from 2 or 3 years back on how to do this this, too.

That has caught a few people

 

[siduramaxde]

That has caught a few people

I'm not exactly sure where the fuel tank is on a T250 but I do believe Bobcat puts the fuel tanks in the same location on all the track machines. With that said, the fuel tank on my T200 is directly under the operators seat. Just lift the cab and it is right there (under a few wires and hoses, of course). I had a wheeled machine before this track machine and the fuel tank was where Tazza described and it was much harder to access than the tank on my track machine