Freightliner M2 with Cummins ISC 8.3 uneven idle, won't rev.

[wrench buster]

Hello, I ran a system pressure test today and it didn't hold within specs. I found inj # 1 was leaking bad when I turned the engine off. I thought alright I found the problem, however that would have been too easy. I replaced # 1 with a Cummins re-man and the rail pressure held within specs. I ran a injector return test under hi pressure and it was within specs. (80 ML) in 1 minute. I am really stumped on this one because it still idles rough and misfires upon acceleration. The HP pump produces 29,000 psi so I don't believe that's the problem. I am leaning towards defective injectors or an ECM issue. If someone can help me narrow this down I would very much appreciate your help. I have no codes, if it was an electrical issue I believe it would throw a code.It feels liike ALL cylinders are misfiring upon acceleration not just 1. When I do the cylinder cut out it seems like very little RPM loss on ea. cyl.

Regards Wrench Buster