Komatsu - engine won't stop!

retskcid · Apr 10, 2009

Hello guys, I came across the forum chasing a problem for my dad.

He has a mini digger type of Komatsu with a diesel engine. Originally he would turn the engine off by the ignition, but now when he switches the ignition off the engine keeps going! Any ideas what could be at fault? What is it that normally stops the engine when you switch off the ignition?

We think we've found either the stop selonoid (can anyone confirm?) or fuel feed pump, the engine runs even with no power supplied to the unit in the pics. if you power it there is intermittent "clicking" and fuel looks like it is being pumped (but is the fuel pump and why does the engine run with it disconnected?).

Our conclusion is that this is the selonoid and its not closing completely. can anyone confirm what the unit is? any help/advice appreciated.

Rich

DarinRay · Apr 10, 2009

That just looks like a feed pump which makes sure there is pressure to the injector pump. Actually with these machien that don't use hardly any fuel they normally have enough fuel being supplied by gravity and will continue to run even with your feed pump off. Send pics of your injector pump and or try to locate the shut off lever and then follow the cable. Let us know how you make out.

Darin

Eagleview · Apr 10, 2009

As Darin suggested , the thing in your hand is a "clicker" type fuel pump . It will click , until the pressure builds and then will stop until the pressure drops , ie leaks back or is used . The lever coming out of the injector pump (unpainted) behind the throttle lever would be the stop control . The three bolt holes in the yellow bracket to the left would be where the stop solenoid should be mounted . Someone has removed it for some reason and may have forgotten they did it ???

retskcid · Apr 11, 2009

Thanks for the advice guys. What we still do not understand is that it used to turn off on the ignition - and my dad has not touched the machine (nor removed anything that I am aware of), its just been in storage for a few years.

So, fuel would pass the pump if it was "off"?

Thanks again.

Rich

fast1 · Apr 11, 2009

sorry what is the selonoid for?

J_J · Apr 11, 2009

There appears to be two levers on the injection pimp. Perhaps one of them is the shutoff lever.

J_J · Apr 11, 2009

retskcid said:
Thanks for the advice guys. What we still do not understand is that it used to turn off on the ignition - and my dad has not touched the machine (nor removed anything that I am aware of), its just been in storage for a few years.

So, fuel would pass the pump if it was "off"?

Thanks again.

Rich

With the engine off, take off the fuel line on the injector side and see if fuel continue to flow.

retskcid · Apr 11, 2009

Iron Horse said:
As Darin suggested , the thing in your hand is a "clicker" type fuel pump . It will click , until the pressure builds and then will stop until the pressure drops , ie leaks back or is used . The lever coming out of the injector pump (unpainted) behind the throttle lever would be the stop control . The three bolt holes in the yellow bracket to the left would be where the stop solenoid should be mounted . Someone has removed it for some reason and may have forgotten they did it ???

Iron Horse and J J were correct, that is the factory stop lever. What we don't understand is where the operating mechanism is now?! Its a mystery, and perhaps its been stolen, but at least we now know how the stop should work. We'll lash something up to the lever.

Thanks for all your help guys, much appreciated.

Rich

Eagleview · Apr 11, 2009

A simple choke cable from an Auto store will do the trick . It will need to be mounted beside the seat to keep the cable as straight as possible and to be easily reached . You will need to make a little clamp to attach to the Yellow bracket to hold the pump end of the outer cable .