does anyone really understand computer and sensors on 89 maxima? runs good until warmed up.idles fine. with load chugs and backfires . won,t go over 10-15 mph. if I turn off ignition for 1 min. willusually solve problem and can run ok for 10 mi. or might start again. if revved to 5k in neutral, sometimes will run good. changed tps for nothing. is it supposed to get richer with load and its backfiring lean. is it inside the computer or can something be sending wrong signal.Help!!!