I have a 2001 B7500HSD, It runs great for about 20 to 30 minutes then starts to lug down. The idle starts to drop and the throttle doesn't seem to work very well. I have drained the tank, had it inspected and scoped by my local Kubota dealer and the tank had no issues. I have replaced the fuel lines from the tank to the injectors. I have replaced the fuel pump in front of the injectors. I have replaced the fuel filter. I have went so far to do a hydraulic fluid service and replace the filters. I have also checked the 3 return lines and found them to be clear. I still have the running issue, Any Ideas?
Rough Running 2001 B7500HSD
- Thread starter dmmartin
- Start date
Have you tried breaking each injector loose while it's running poorly to see if it's a certain cylinder? Another thought is trying to run off of a clean and known good fuel source, right of the supply to the injection pump.
Pat
Pat
Sounds like your attacking the correct area (fuel delivery).
Some wild guesses...
Some wild guesses...
- Did you verify good fuel flow pre and post filter?
- If there is an electric lift pump, it might be overheating and failing since it takes time for the symptom to appear.
- Is the tank well vented. If not, fuel usage could cause vacuum inside the tank causing fuel flow degradation.
I was advised not to mess with the injectors while running due to high pressure, I also tried a saddle tank no change in the running of the tractor.
I have drained the tank before and after the filter, appears to be the same flow rate. There is no electric fuel pump on this model. I have run the engine with the cap to the tank loosened with no change in the running of the engine.
85Hokie
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I would say you have something in the ol' tank, after a little vibration, IT is working itself to the fuel pickup. Could be anything, broken fuel sending unit, some algae, or even something like like the silver tap of a fuel treatment cap!
The tank has been drained, flushed and rinsed out. The sending unit is brand new as well, I installed it. I also filter fuel going into tank.
What 1970cs was suggesting is to simply loosen the nut at the injectors, one at a time, so you can detect if that particular injector is functioning properly.
You loosen the nut with a 19MM wrench a couple of turns only. If no change is made in the engine, you have a problem in that cylinder.
Do not take the line completely off, only loosen.
You loosen the nut with a 19MM wrench a couple of turns only. If no change is made in the engine, you have a problem in that cylinder.
Do not take the line completely off, only loosen.
What D2Cat is saying is great way to check that each cylinder is doing it's part. My own experience would say " Loosen the nut a couple of FLATS only" Not full turns. All that is needed is to bleed off pressure, The fuel will just dribble down from the nut. I suppose there is danger if you only crack the fitting a very small amount and high pressure fuel spurts out.
Wear safety glasses. Throw a rag over the fitting after the wrenches are placed. Use a back up wrench on the injector body!
Wear safety glasses. Throw a rag over the fitting after the wrenches are placed. Use a back up wrench on the injector body!
Yes, I should have said line, my bad! But you have ran off another fuel source so you're down to injection pump or injector.
I had a blue tractor do that to me! The injection pump was sent to a very qualified shop. Came back with same issue. I told the tech there, I was certain it was the pump, he said send it back! He tried to find the issue 3 times. Finally I said put a damn heat gun on it while it was on the test stand.
Guess what, it started dropping a cylinder while it was hot. If memory serves it was a cracked body on the pump. His mistake cost me over 20 hrs of labor second and third guessing myself.
Same style of injection pump that you have.
Pat
I had a blue tractor do that to me! The injection pump was sent to a very qualified shop. Came back with same issue. I told the tech there, I was certain it was the pump, he said send it back! He tried to find the issue 3 times. Finally I said put a damn heat gun on it while it was on the test stand.
Guess what, it started dropping a cylinder while it was hot. If memory serves it was a cracked body on the pump. His mistake cost me over 20 hrs of labor second and third guessing myself.
Same style of injection pump that you have.
Pat
I broke down and had my local dealer pickup my tractor today. The problem was getting into area's beyond the scope of my experience. Thanks for all the help. Dave
Well Finally got the tractor fixed, turns out it was bad fuel. Not having a sense of smell is hindering at times and this was one of those times.
Well Finally got the tractor fixed, turns out it was bad fuel. Not having a sense of smell is hindering at times and this was one of those times.