z930m EFI loses power after 20 minutes

[Ranchito]

Yes

Only proves that the engine will run at no load even with low fuel pressure. I regularly clean automobile fuel injectors at less than system pressure and the engines will run fine at no load idle. Pressure gauge at injector rail proves it is or isn't fuel pressure related. Doesn't hurt to check fuel volume also. If pressure is in spec, what triggers the injectors? A crank sensor? It would be hard to see a bad crank sensor without a scope, but maybe it would throw a code. The Kohler experts here could comment on that.

 

[ILENGINE]

Only proves that the engine will run at no load even with low fuel pressure. I regularly clean automobile fuel injectors at less than system pressure and the engines will run fine at no load idle. Pressure gauge at injector rail proves it is or isn't fuel pressure related. Doesn't hurt to check fuel volume also. If pressure is in spec, what triggers the injectors? A crank sensor? It would be hard to see a bad crank sensor without a scope, but maybe it would throw a code. The Kohler experts here could comment on that.

Bad crank position sensor would throw a code also wouldn't fire the plugs or energize the injectors. Basically if the engine doesn't know were it is it doesn't work.

 

[StarTech]

Reading thru the thread this morning.

A couple things I notice one is problem occurs under load so it be an ignition problem under load. Also as mention crank position could have a too large of a gap.

The JD service manual does not cover this problem for the Z930M and I have that manual on my system.

 

[FisherCat930]

Just a quick followup. I purchased the knockoff EFI pump and mowed with it at full-throttle for about 2hrs yesterday and so far it appears to be running fantastic. It was a little cooler here so we'll see what happens when I mow in the heat next time. I have no expectation that this pump will hold up forever, but for the sake of trying to figuring this issue out I'm pretty happy so far. I also put a new fuel filter on with a smaller micron size as was suggested here.

Gonna see how it does over the next few weeks and will post back with the report. Thanks all!

 

[Ranchito]

Reading thru the thread this morning.

A couple things I notice one is problem occurs under load so it be an ignition problem under load. Also as mention crank position could have a too large of a gap.

The JD service manual does not cover this problem for the Z930M and I have that manual on my system.

Is the gap adjustable? Was a Mopar problem. Replacement sensor had a paper sticker on the end that set the gap and was wiped away at initial engine crank after replacement.

 

[StarTech]

Just a quick followup. I purchased the knockoff EFI pump and mowed with it at full-throttle for about 2hrs yesterday and so far it appears to be running fantastic. It was a little cooler here so we'll see what happens when I mow in the heat next time. I have no expectation that this pump will hold up forever, but for the sake of trying to figuring this issue out I'm pretty happy so far. I also put a new fuel filter on with a smaller micron size as was suggested here.

Gonna see how it does over the next few weeks and will post back with the report. Thanks all!

Tnx for the update and good luck. Just another thing for me to keep in the back of my mind for later troubleshooting when I get an EFI system in.