Older Perkins Diesel won't stay running. HELP!

[tc40da-rg]

I have an old (1983, I believe) Massey Ferguson 3-cylinder Perkins diesel that simply will not keep running. It began losing power while bush hogging. It would "rev up" a little, then lose rpm. It would repeat this with an added "knock"/ping before slowing down every few minutes; then repeating at closer intervals before finally going dead. The fuel pump was rebuilt about 2 years ago. I removed the tank and cleaned it (there was NO trash, "gunk", etc. in the tank at all! A major miracle considering it has never been cleaned in its lifetime!). Blew out all lines, replaced filter and made sure there was good fuel flow from the tank all the way to injectors. It ran/idled smoothly for 20 minutes or so; then began the old process all over again! It almost seems as if there is something (in the injector pump???) that is binding once it gets hot. But if it is a "heat" problem, why does it not want to start (without use of ether) after cooling off? Or, maybe it is sucking air from "somewhere"? I have taken the fuel system down and back three times now, with no change in results. I'm no diesel mechanic anyway, but this sure has me stumped. Has anyone run across the same symptoms?

After the last "take down", it started (using ether) and ran for 20 minutes with a perfect idle. All at once, it revved up rpm's as if it was being fed gasoline or ether. It then idled properly for a few minutes, then had a very hard "knock" (as if trying to run backward all of a sudden), lost rpm... then continued to idle again, but only for a few minutes -- after which, it repeated the sequence about 6 or 7 more times before finally dying. It would not crank (run -- it does spin over very well) on its own again. It will start and run immediately with the input of ether (starter fluid spray), but dies as soon as the ether is stopped. I tried it (without ether) the following morning, and it "seemed" like -- for just a second -- that it might start/run. But then just spun over and over without any further signs of "firing".

I will be extremely grateful for any/all help on this one, as I am in desperate need of having this tractor operating. Thanks in advance TBN forum.

 

[Jerry/MT]

I have an old (1983, I believe) Massey Ferguson 3-cylinder Perkins diesel that simply will not keep running. It began losing power while bush hogging. It would "rev up" a little, then lose rpm. It would repeat this with an added "knock"/ping before slowing down every few minutes; then repeating at closer intervals before finally going dead. The fuel pump was rebuilt about 2 years ago. I removed the tank and cleaned it (there was NO trash, "gunk", etc. in the tank at all! A major miracle considering it has never been cleaned in its lifetime!). Blew out all lines, replaced filter and made sure there was good fuel flow from the tank all the way to injectors. It ran/idled smoothly for 20 minutes or so; then began the old process all over again! It almost seems as if there is something (in the injector pump???) that is binding once it gets hot. But if it is a "heat" problem, why does it not want to start (without use of ether) after cooling off? Or, maybe it is sucking air from "somewhere"? I have taken the fuel system down and back three times now, with no change in results. I'm no diesel mechanic anyway, but this sure has me stumped. Has anyone run across the same symptoms?

After the last "take down", it started (using ether) and ran for 20 minutes with a perfect idle. All at once, it revved up rpm's as if it was being fed gasoline or ether. It then idled properly for a few minutes, then had a very hard "knock" (as if trying to run backward all of a sudden), lost rpm... then continued to idle again, but only for a few minutes -- after which, it repeated the sequence about 6 or 7 more times before finally dying. It would not crank (run -- it does spin over very well) on its own again. It will start and run immediately with the input of ether (starter fluid spray), but dies as soon as the ether is stopped. I tried it (without ether) the following morning, and it "seemed" like -- for just a second -- that it might start/run. But then just spun over and over without any further signs of "firing".

I will be extremely grateful for any/all help on this one, as I am in desperate need of having this tractor operating. Thanks in advance TBN forum.

Quit using starting fluid before you break the rings!

"Blew out all lines, replaced filter and made sure there was good fuel flow from the tank all the way to injectors. It ran/idled smoothly for 20 minutes or so; then began the old process all over again! "

It sounds to me like you haven't found what's blocking the fuel flow. Depending on how you do it, blowing out a line can blow debris back into the tank only to eventually re-clog the fuel delivery system.
Is your return-to-tank line returning excess fuel to the tank? It may be plugged.

 

[windy acers]

REPLACE FUEL/LIFT PUMP

 

[tc40da-rg]

Thanks for the input and suggestions, Jerry. The fuel lines have allowed (clean) fuel to run freely since first experiencing the problem, so I'm pretty sure there isn't any debris in them blocking the fuel flow. In fact, we haven't found ANY signs of debris, water, gelling, rust, etc. anywhere in the entire system. I actually have not checked the "return-to-tank" line for any flow, but it was clear and allowed full flow when we serviced everything. I will recheck it tomorrow when I return to the farm (I live 160 miles away from where I have the tractor/farm).

Oh, and I do understand the risk involved with using the starting fluid... it is simply the ONLY way it has started/ran 50% of the time since this problem began.

 

[tc40da-rg]

Thank you, Windy Acers. I have been hoping that this is not the culprit, since I spent quite a bit on having it rebuilt just a few years ago; but, it is looking more and more like this may be the problem. I was just hoping that someone had experienced this before and would tell me, "oh, that's a simple and inexpensive fix!" Ha! Well, that's what I wished for. *I can hear my dad now: "Son, wish in one hand and (spit) in the other, and see which fills up fastest."

 

[GManBart]

Thank you, Windy Acers. I have been hoping that this is not the culprit, since I spent quite a bit on having it rebuilt just a few years ago; but, it is looking more and more like this may be the problem. I was just hoping that someone had experienced this before and would tell me, "oh, that's a simple and inexpensive fix!" Ha! Well, that's what I wished for. *I can hear my dad now: "Son, wish in one hand and (spit) in the other, and see which fills up fastest."

It sounds like you're confusing the fuel lift pump with the fuel injector pump...two different creatures. The fuel lift pump is a small cam operated pump that mounts on the right side of most Perkins engines, and is considered a weak point....they sometimes last 1,500hrs, and sometimes 100hrs. The good thing is that a new one is only about $40. When they fail, the engine exhibits the exact same symptoms you're describing.

The lift pump looks like this (without the lever on the left being visible) and it bolts to the right side of the engine.

 

[crankshaft21]

Before replacing any part, make sure the fuel tank cap is vented. If it gets stopped up, and tank can`t breath, that will cause the same problem.

 

[6sunset6]

The lift pumps have check valves in them basically rubber flaps. If a piece of junk get in there the pump will not deliver any pressure to the injector pump.

 

[tc40da-rg]

Thank you, again, GMan. You are correct; I jumped to conclusions-- expecting the most expensive/difficult repair. Picked up a lift pump this morning and will give it the test in just a little bit.

 

[tc40da-rg]

Good advice crankshaft 21. Will check it first thing when I get to the tractor (But, it's only 31/32 years old, don't know why it wouldn't be good. LOL)