missing problem JD

[Graper00]

I have a 300B JD industrial tractor 3cyld. that has a pretty good miss in it and i'm having a hard time tring to find it. I have adjusted valves, pulled the injector nozzels and replaced washer seals (not carbon seals though), there are no leaks in fuel lines. I can't tell if it is a bad injector or a bad valve. The engine has a cutout/popping to it. I can crack lines to injectors (with engine running) on all 3 cyl and the all miss even worse. So injectors should be ok and I should do a valve job on it?

 

[W5FL]

Please run a compression test first. It is very easy to do and will answer your questions as to valve condition. Also need to know the timing that the fuel is being injected. I suspect you can get an idea by feeling of the exhaust and air intake, but compression test will still need to be run.