New to site. 6.5 prob please help

[dcrdually]

I have 94 dually with 6.5 turbo diesel. It started stumbling or missing at cruising speed and now when you start (http://www.dieseldoctor.com/diesel-board/general-diesel-discussion/please-help-t8801.html#) it, it revs to about 2000 rpm. If I unplug the optical bump on the pump it gets hard to start and idles rough but will at least drive. It also poors black smoke when you give it throttle and stumbles hard at cruising speed. Any help would be greatly appreciated. Thank you.

[racer55]

Sounds like a flight systems PMD failure to me.
Check the PMD harness for corrosion and the resistor for corrosion first though.

[greatwhite]

Sounds like a flight systems PMD failure to me.
Check the PMD harness for corrosion and the resistor for corrosion first though.

X2.....:cool:

[dcrdually]

thank you. I will check that.

[greatwhite]

Forgot to add to pull the trouble codes from the PCM to see what's lurking in there...