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Posted

OK here goes.  I have a cub cadet volunteer with a fuel injected Kohler lh775.  This was brought to me from another shop since they couldn't figure it out.  

Here's their story.

came in for a water pump.  tech pulled the intake and a few other misc parts and replaced the water pump.  Reassembled and the motor was missing on cylinder 2.  replaced several parts and just couldn't get it to run on both cylinders.

 

So in my shop we checked compression 155ish on both cylinders at wot.  I can get the motor to start if I hold the gas pedal in just the right place but at low RPM's it very rough.

Pulled side cover and verified timing is correct and key ways are not sheared

turned over motor with injectors out and they spray evenly and the same. best I can tell by eye

installed new plugs and got motor to start and held it at higher RPM's for a few seconds.  cylinder 1 plug is dark cylinder 2 is still new and seems  damp with gas

switched coils from 1-2 installed new plugs again and same test with same results.  

The other shop replaced the ECU and harness.  No matter what parts I switch from cylinder 1 to cylinder 2 the problem stays on cylinder 2.  

 

Any thought or ideas would be greatly appreciated  

Posted

That's interesting because swapping parts you get same results. Is the plug in cyl 2 firing? If so, its gotta be something mechanical, although compression is good you said. I'm leaning on spark and/or timing issue.

Posted

I agree I have had a spark checker on both cylinders during the checks. Both coils are firing. I have also had 3 new plugs in cylinder 2. The first I changed to run the motor and read it and ever time I ran it with cylinder 1 parts.  So  kinda got to rule out spark. 
 

when I had the motor out I checked timing and key ways. All are good. I even turned the motor over by hand several times and watched the valves in regard to piston stroke. All is good. Piston goes down intake valve opens. Both valves close piston comes up for comp stroke then exhaust valve opens. Did this on both cylinders probably 10 times. Timing marks (crank mark@12 o’clock and cam mark @ 6 o’clock ) every 4th revaluation. 

Posted

Last effort swapped injectors. Verified fuel pressure and same. Cylinder 2 not firing. Plug looks new coming out and no heat in cylinder. Sent it back broke. 😒😒 feeling defeated. 

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