Miss in 6.5 TD - Injector Balance Test?

[CapnAmerica]

My 1996 GMC Sub has a slight miss, which I suspect is a bad injector. I have done some injector swapping around and haven't hit the right one (if this is indeed the problem...). (Injector swapping in this truck is a bit painful on the passenger side bank! The less, the better...)

I have an AutoEnginuity interface to my laptop, which will perform the test--I can shut off any one of the injectors, which is pretty neat! However, I would like to see a pronounced drop vs. NON-drop in engine speed when I shut off the offending unit, but I don't see such a difference. Has anyone got a procedure that would help to pinpoint my problem with this equipment setup? As info, I have the timing set as close as I can to the recommended (by you folks, not my Friendly GMC Shop!) -1.94 deg., and it seems to run a bit rough vs. factory spec. This might make it hard to spot the change in RPM. Any help or thoughts would be appreciated.

Thanks!
Capn America in TN

1996 GMC Suburban 6.5TD K1500 w/various gauges on the pillar, boost booster for 12-15 psi, PMD in front of the left battery w/cooling fan, trans shift helper, autolockers all around, reamed out intake w/K&N, 4" exhaust, 240,000 on the clock, a little taller than normal.
1985 Chevy Suburban 6.2NA w/383.000, Swangerized intake w/BIG intake pipe, some odd 700R4 w/manual TCC switch.

[gmctd]

Should be easy to spot in Cylinder Balance test at idle - PCM monitors crank velocity differences for each individual cylinder at idle, logs DTC 91-98 for cyls 1-8 if not able to maintain rpm

[CapnAmerica]

The problem seems to be that the variation in RPMs at idle, and even when I reset engine speed to, say, 1200, is greater than the change when I shut off one injector. Thus it's difficult to pick out the offending cylinder/injector. I'm hoping for some magic from somebody which will help me read the difference.

[rjwest]

If it is missing only underload, I doubt the Dead cylinder test will find it,

My Miss was at TCC lock up rpm only, higher RPM's was ok,
It was an injector pump, found this out when I
Had intermittent warm up fish bite and 'quits'

which was defenitly NOT the PMD, ( many replaced )

After changing IP, Miss was also cured, and swapped PMD"S all ran good...

I had -1.94 set for awhile, Just to much cold start noise
for me,