E-test wrecks engine????

So I took my '98 T800 w/M11 Cummins in for it's E-test yesterday. Gov't test sipulates that the tester must hit the "governor" and hold it for a couple of seconds and repeat 5 times for a total of six times. Truck passed so well I got an exemption for next year, but now I have a bad miss. No smoke, oil psi normal, temps normal. Gonna pill the vavle cover tomorrow to see what we can see.

Any guesses?

 

My mechanic couldn't find anything today but he agrees there is a miss. Yes going to do a cylinder cutout tomorrow. My infra red thermometer shows all exhaust ports at 110 - 115 degrees C except #6 which is 95-100.

Last time this happened (Jan 2012) the dealership said it was not an injector because the rpms didn't change on the cylinder cutout test. They said wiring harness....nope, then they said ECM...nope, then they said tone ring....nope. Finally after many hrs spent diagnosing, and several requests by me, the service manager agreed to go for a ride with their laptop plugged into the dash port and it showed #6 was bad under load.

If I am right, this will be the 3rd #6 in 2 yrs.

Thanks for the tip on the bare wires.