[quote=marin8703]One reason that I know of the engine going into reduced power would be high temp. If it over heats it goes into reduced power mode in an effort to reduce engine temp by reducing power output while keeping fan and cooling system at max.
I would have said its normal for all vehicles to loose power with altitude increase because of lower concentration of oxygen which is needed for combustion to occur, but since it was ok after restart it leads me to believe its an overheating issue. I might be wrong, wouldnt be the first time!
oh and it also could have detected a misfire and went into "protect" (reduced engine power) in order to prevent it from misfiring again, keepin the engine safe or sum like that.
What was your temp gauge showing? and what temp were you playin in?
hope i was of any help.[/quote
Thanks for the input. The truck did have multiple missifres in a row while it was doing this. The temp stayed the same all day at normal.
I did have this happen in my SUT when I had it. It needed a computer upgrade and a new fuel pump/ sending unit, but the engine light never went back out. Same symtoms at altitude only.