190XTafter - developing low power

My 190 has been workrd hard lately and today is not running well. The engine seems smothered down and cannot rev up. This follows a couple of days where the engine has been running high  and low. It would be running at moderate power and suddenly rev up and run really strong with good rpms to the pto. That would only be for a minute and then it would drop back down in power and pto speed. The tractor has not ran at the better power for a ong time and followed a recent servicing. About 2 wks ago I changed oil & filter, air filter, fuel filter, and hydraulic fluid & filter after the transmission would quit pulling and the steering got bad. The servicing seemed to fix those problems but now the enging is sputtering & weak. I have checked the settling bowl and it seemed ok with good fuel flow from the tank. What would you check next?

Thanks Orange Blood for the advice. I was not able to check it today a much as I would like but tried some of this. My guess was that the return line was the top one and I separated it and ran the engine for a few minutes. The metal line had about two inch rubber tubing at certain points and one of them was very loose. I tightened the hose clamps. The diesel looked clear and no black specs were seen. I could not determine if bubbles were present but will check again tomorrow.  On the inlet side, I did not see any obvious place the lines could be getting air. The shut off lever and throttle seem to work well and the engine revved up well while setting still.  Am I on the track you described?

I will take the top fitting off tomorrow and it is a good thing to know that an air leak is not always a fuel leak. Two things you mentioned may be a problem on my 190. I believe it only has one sediment bowl although it has a plug where another could be added. Ihave cleaned the bowl twice since I had problems here several years ago with the fine screen in the top of the bowl stopping up after starting the use of fuel system cleaners/treatments. Also, myhand primer has never been very good. It seems that fuel spills so freely from it I really could not tell if it primes on the push or the pull. It gives you a diesel bath either way.  Thanks.

I understand needing it to run, as long as you aren't lugging it down, it really shouldn't be a problem, but it really needs to be fixed soon, since starving a pump for fuel, if that's the issue is hard on them.  Anyway, you mentioned something earlier that peaked my intrest, you started running fuel system cleaners.  I am still betting it is fuel starvation even if the steel lines are not pinched or bent, Benny is still possibly correct, what may have happened is some stuff came loose back when you were running cleaner, and when running it lately it started moving toward the pump, and lodged in a fitting or some other area restricting flow.  When I ask you to check flow at the Injection pump inlet, I mean take the line off, and open the tank valve and see just what flow you have, it should run out fairly well if the tank is half full or better.  Also if the return is restricted that could also be a problem if it builds back preassure.  Just some things to think about. 

Orange Blood, I will check the inlet tomorrow before finishing raking. I would not want to damage the pump and I do think the problem is fuel flow based on what you have said. Tracy's experience may be part of the reason I was using the Lucas several years ago. The Lucas released a black oily substance from the tank that stopped up my sediment bowl screen that I referred to earlier. I almost had the pump rebuilt then but the fuel system cleaner smoothed out the running. If I am not getting good fuel flow at the pump inlet, can the line be blown out with air without causing any other problems?

Had a similar problem with a D3C cat dozer tuned out it was a few pine needles getting pulled into the fuel line every time it started to work a little hard.Took me weeks to finely figure it out. Good luck finding the problem. 

Took off work at noon to utilize the advice offered here. By the time drove tractor from field to house, about half a mile, power dropped to point tractor went dead in driveway. No gravity flow at pump inlet and pressurizing tank only pushed small amount of fuel out at inlet. Took fuel lines apart back to tank, drained tank, blew everthing out, refueled with filtered fuel, and it cranked and ran smooth. Will try it in field tomorrow. Found lines to be mostly clean except for primer inlet and minor trash between tank and sediment bowl inlet. The primer had a good amount of paint flakes and debris in the spring. The fuel tank was very clean and the drained fuel had minimal small specks. I hope this gets me running again, I'll see tomorrow. 

I will know tomorrow. I was surprised at where the most blockage was. Thought it would be in the tank or sediment bowl inlet and almost did not take the primer apart. Your advice was great and maybe I will be going strong tomorrow. The engine did run smoother than usual sitting still. Thanks.

I am finally getting started baling hay after the fuel system delays and the 190 is running smooth. I had one small problem about 30 minutes into raking when I reduced throttle to stop and remove a limb and the engine went dead. I worked with it for about 15 minutes and it started again. It ran smooth with no additional problems to finish raking and baling about 6 acres before the fog rolled in near dark. I think it is fixed and I will tackle the other 12 acres tomorrow. Thanks for all the information and directions.

I had the same problem a couple years ago.  Did the things people has suggested.  Helped for a little while.  Had to give in and have the injection pump rebuilt.  Now it runs fine and does not quit.  Around a $600.00 fix here in WV.