Kohler Command Pro CH 745 Bosch EFI 28HP running issue

Hi I have an old Exmark Lazer Z with a command pro CH745 engine and Bosch EFI system.

Last year I replaced the head gaskets. It ran fine till the end of the mowing season.

At that time it would shut off after mowing for about an hour and a half. Would crank and not start. Fuel pump would click on and off. Then after cooling off it would start again.

I replaced the fuel pump but it was still doing the same thing.

I just started it up and used it for the first time this year. Same issue ran for an hour and half then shut off and would not start. After it cooled off it would run but not well, surging, missing, seemed like a fuel problem. The relay for fuel pump(I think) kept clicking.

This time it has a code 23 - defective ECU.

Anyone have experience with this. Do ECU's go bad and cause issue like this? Before spending the $$$ for an ECU could there be another cause?

Thanks

Check the oil make sure it's at operating level. It's not a real common issue for them to go out but have seen them go bad. Also when you run it and you turn it off and when it goes to the no start issue check the spark and verify it has it. Last if you can find a expert kohler dealer or a dealer who sells kohler efi engines should have the diagnostics kit that they should be able to hook up your engine test the history and current issues with your engine. If all fails call kohler talk to a tech they can point you In the right direction to get you up and running. Simple things tank cap venting,oil,spark, if you have a spare tank that you can use to verify good fuel flow and your line is not closing up when this no start happens also could use and little starting fluid verify some like fuel and spark. Keep us posted

http://resources.kohler.com/power/kohler/enginesUS/pdf/24_690_01_EN.pdf

see troubleshooting section