Komatsu FG25ST-16:
No Spark on 2 Cylinders

Looking for suggestions. K21L Engine 2008. Only 2 cylinders are getting spark. Will start and run on the 2 good cylinders but barely. I've replaced all 4 ignition coils and spark plugs just to rule those out. Any advice where to look next? We are located out in the country so calling anyone to come look at it requires an expensive travel bill for a tech or I have to have it towed into town. Trying to rule anything out first before going that direction. Thanks!!!
  • Posted 19 Jan 2022 10:35
  • Discussion started by Ryan231
  • Kentucky, United States
Showing items 1 - 2 of 2 results.
If as the last post said is not the problem the next step would be to check the wiring to the two coils that are not firing also is the engine light on for a Misfire code there are three wires going to each coil you should have 12volts on one wire the other wire should be ground and the last wire is the driver output from the computer check all the wiring it is possible that two drivers are bad in the computer that would not give you spark to the coils but check the wiring also see if there is any other codes in the computer like a cam or crank code. If you need the wire numbers to the computer get back to me and l will look them up.
  • Posted 26 Jun 2023 00:28
  • Reply by Scott_
  • Pennsylvania, United States
Scott
Make sure the ign coils are plugged I to the spark plugs. I have seen people put all 4 of them on together and miss the top of the spark plugs on a couple of them.
  • Posted 22 Jun 2023 13:26
  • Reply by Persley
  • Arizona, United States

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