Just ran around the block chasing similar symptoms on a Nissan- check the ignition spark- should be bright blue & be able to jump at least 1/2" w/out changing engine performance- check this at each plug- not off the coil. Never had a dist cap 'eat' spark before but this one was a challenge to find. 1 terminal in the cap almost totally dissipated all spark which didn't show any symptoms except when engine cold or under load. Woulda' bet the house there was a fuel issue.