Left key on overnight and now idles rough, no power.

[halfoak]

I accidentally left the ignition key on overnight and now my truck starts hard, idles rough, and has no power. The truck is 97 F350 7.3D Manual tranny with 250,000 miles. I tried disconnecting the battery for a few hours to reset the computer, but that didn't help. Check fuses, they are ok. Any suggestions on what part(s) may have burned up by having the key left on?

[Welderman2008]

mightve fried the GPR or GP's might account for the hard starting....

[madpogue]

Key left in RUN, cold engine, the glow plugs will still only run for the first two minutes or so. Did you happen to look-see (or feel-see) how hot the PCM and/or IDM were when you went out and discovered the sitch?

Batteries would be low, requiring extra current from the alternator, lowering the voltage for a while; dunno if that would affect the power, though (maybe lowering the injector voltage?). Did you try throwing the batteries on a slow charge?