Intermitent MIL, code 1271

[GAS]

99 F350 (1-99 manufacture date)201k miles. Check eng light comes and goes
Light comes and goes almost in sync with on or off throttle. Starts fine, no miss that I can feel, decent power/fuel economy.

Code for KOEO test 1271,, Open in #one cylinder, high or Low.

Took off VC and tested continuty, Good. Even went so far as to remove gasket and harness to test on bench while wiggling stuff, Still OK.

Ran cylinder balance test, OK.

Ran Buzz test, multiple times. First time, repeated 1271 code. Also noted that the first cyl in test was loud as hell, and buzzed longer than the rest???
The repeated test still had the loud injector, just no codes

Is the Loud Buzz an indicator of a bad injector?

I am a small shop owner/tech, diesels just aren't my forte'
Throwing parts at a vehicle just isnt my style, I like to find a smoking gun.

And,since this just happens to be my tow vehicle for the race car I really wanna get it right.

One tech to another??
Micha

[GAS]

any one?