lack of power, 95 trooper, manual tranny
 

1995 Isuzu Trooper 170k, manual transmission

when 'tired' (i.e. after some hours of driving), engine will rev when i press accelerator pedal, but little to no power will come... has been doing this off and on for a few months, mostly on hills, but occasionally on flat.. usually from stop, or low speeds, and i can usually get it going, slowly, then at highway speeds it's fine.

comes and goes, one minute it's there, then gone, another 1/2 hour it's back for bit. worst when on hills when tired, i.e. driving into mountains... usually goes away once car is rested, or on flats for a while... but seems to be getting worse...maybe.

my mechanic gave me a blank look, like he'd never heard of such a thing.

any tips greatly appreciated!