komatsu wa 800-2 hard starting

[excat]

we have a fuel system problem with this machine.
1.at start up cranks over ok but won t fire ,crack lines at injection pump no fuel when cranking.
hand prime system lots of air at fuel filters etc.
after priming machine starts and runs ok.
2.machine runs ok but intermittantly will shut down as if it has run out of fuel. prime system and again runs ok.
3.some times at start up after fueling machine it runs on one bank,crack fuel lines on injection pump on bank not running and no fuel.

again have to hand prime fuel system to get it to run.

this is an on going problem that the dealer has been had many goes at repairing with no result.
can anybody help !!!
regards greg

 

[John C.]

Check for fuel strainers between the tank and the fuel pump. Usually on the bigger machines they have a mid size canister with a bolt head cap on the end. They will also put small strainers in banjo bolts on the inlet tubes to the transfer pumps.

Good Luck!

 

[toomanymachines]

I would guess that you may have a cracked fuel line, on the suction side of things. How many hours do you have on it? I had an old landcruiser give me issues, It ended up being a fuel line had rubbed against another and never showed a leak I ended up finding it becasue I over filled the tank right to the top of the neck and then it raised it evil little head up. If the fuel tank is too low you could try to pressurize the tank (with a rag and air gun) and push the fuel, it may show a leak.

 

[excat]

all suction hoses and both lift pumps have been replaced.
fuel tank removed ,holes cut in sides and cleaned out,refitted etc.
fuel tank pick ups inspected for cracks etc.
it appears to be getting air in the system but can,t find were and only intermittantly some times it runs for a few days with no problem others a few hours and then problems,it does not matter what the fuel level is when problem occurs.
fuel suction screen cleaned and new seals fitted when problem first occured.
regards greg

 

[bwmwaima]

Check tank breather.

 

[excat]

been replaced.

 

[CAT793]

Cut a fuel filter and check for Carbon?

Injector seat allowing combustion into the gallery.

 

[excat]

will do this as soon as i get back to the machine.
thanks for the reply.
regards greg.

 

[hootsmcgoots]

I don't know if there's any differences in the 900-3's engine and the 800-2's, but there's a block that splits the fuel from the tank and sends it to the different sides of he engine. On the 900, it's on the left side of the engine ( right side of machine) just above the oil pan. I've seen a few of those get hairline cracks and it will only fire on one side while sucking the filters dry on the other.