Injection Pump Question

[Jo Bird]

My small 2 cylinder diesel engine was running and quit. Tried to restart to no avail, pulled the oil level dipstick on the side of the injection pump and flood of fuel poured out from the body cavity. Any one have a clue how it was able to get in to the body of the pump ? My thought is possibly from the hand primer on the side of the pump .. Pulled it apart and the body was full of silt, not sure where all that came from. Cleaned it out and reassembled it , going to put it back on the engine and see what happens. Any incite as to how or why this occurred , the fuel filter/ water separator should have prevented this. Don't really want to spend the money for a new pump if their is an easy fix.

 

[JDEM]

It might help the conversation if you mention what sort of pump or what model tractor? I assume (but do not know for sure) you have
separate piston injector pumps - one for each cylinder. Unlike a distributor pump that has just one central pump that gets its charge
distributed to one cylinder at a time. Fuel oil can get into the main pump body via the transfer pump, or just the injector-pump
barrel/plunger itself. In fact, some are designed to leak. E.g. the in-line CAV pumps used on British IH tractors that have a pigtail
overflow so excess diesel fuel comes out and drips on the ground.

 

[Jo Bird]

JDEM , Sorry about that , the tractor is a McConnell 245 or rather a re-branded Chinese Jinma . There is a tag on the pump , but I don't read Chinese . From what I can tell it is separate piston injector pump - one for each cylinder. I normally leave this type of repair to the experts , that is, just ship it off the a local repair shop. Of course they don't care for an oddball pump such as this . So I figured I take a shot at it , worst case , I'll buy a new pump.

 

[JDEM]

I am not familiar with your specific tractor. That said, after you mentioned the silt inside the pump body - I am wondering if you have
any plungers that got stuck? Again, I am not familiar with your exact machine. I know back with many of the Ford diesels that used Sims
inline pumps - they would run dry in the cam-box until the plungers got stuck and the engine would die. I freed up many with a pry-bar, put
oil back in and the tractor ran fine again. Pretty rugged I guess. But - something like a Ford 4000 with a Sims has a cam-box that the
four pump plungers ride on. Does you engine have a cam box? I ask because many Asian diesels use plunger pumps that ride on a cam that
sits in engine oil and does not have its own fill. My International Harvester has a CAV in-line pump and it too has a separate oil-fill in
the cam box. It constantly overflows with diesel fuel and I am sure more then it was designed with. I know with mine is it excess leakage
from the pump barrels.

If your plungers go up and down (are not stuck), and they are getting fuel, seems it ought to run. If not getting fuel, I guess you have
to find out why.

 

[Dieseltech]

If the silt has been inside the pump, I'd suspect a filter is not doing it's job either. I had a Ford Shibaura in awhile back, plungers and nozzle tips all stuck do to a filter that did not seal, allowing trash to pass. All plunger type pumps do bleed some fuel past into cam area, newer are less as they are ducted internally to cut the leakage down. If the plunger top and helix areas are damaged, that will keep it from starting and new plungers or complete pump will be needed.

 

[Jo Bird]

JDEM
Yes , my pump has a cam box, with and oil fill separate from the the plungers. Did not get time today to put it back together, but will reassemble and try to start the engine. Now thinking as Dieseltech pointed out the filter my have been the route cause of the problem, so I will change that as well. Possibly the injectors may be plugged as well from the sludge . Can they be taken apart and cleaned ? Want to thank both of you for your advice.
Jo

 

[Dieseltech]

The injectors should be checked on a pop tester at least, and if opening pressure and spray work OK without dripping, would be safe to use again. If they are stuck closed you will see that on the tester too. If not tested, and any are stuck closed you most likely WILL split a pump barrel, making maters worse.

 

[Jo Bird]

(quoted from post at 16:19:37 05/09/19) If the silt has been inside the pump, I'd suspect a filter is not doing it's job either. I had a Ford Shibaura in awhile back, plungers and nozzle tips all stuck do to a filter that did not seal, allowing trash to pass. All plunger type pumps do bleed some fuel past into cam area, newer are less as they are ducted internally to cut the leakage down. If the plunger top and helix areas are damaged, that will keep it from starting and new plungers or complete pump will be needed.

ieseltech / JDEM
After a complete tear down, I see no visible damage to the plunger top and helix areas assembly. Their was no foreign material in the top assembly. I am leaning towards the seal on the hand primer/ pump assembly as being the area that failed letting fuel enter the lower pump housing. How ever after reassembly I am not getting fuel out the top of the injector assembly. If I loosen the top of the injector hold down, it will pump fuel, the pump only has 80 hours of run time, its hard for me to believe that in that short amount of time enough wear would be present to keep it from working. My assumption at this point is that, I need a new pump or plunger assembly. Do you concur with this diagnosis or am I missing something. Any incite is greatly appreciated, thank for your time.
Jo