Cat hauler

Can anyone suggest a solution to a problem miss in the 335 Cummins engine
in our Mack LTH Cat hauler? One cylinder misses at idle when the air pump
is pumping and smooths out as the air governor cuts out. The compressor has
its own external intake filter and does not take air from the aftercooler.
Also equiped with a three stage Jake brake. Suggestions appreciated.
Thanks, Lou

It is possible that you notice the miss when the air compressor is pumping because of the lower rpm. It is possible that you have an injector that is bad. Pull off valve covers and cancel out each injector indivdually. Listen for the cylinder that does not change in sound. It could have a bad lobe on the camshaft, 335's with Jakes were bad for this.