1990 Mazda 626 Car starts, idles and runs very well when cold however whwn its hot the car is hard to start and stalls. So far the idlde air cotrol valve and mass air sensor have been replaced . Each...
Honestly sounds like the throttle position sensor, if the car is cold it will be choked and thus the throttle body flap almost closed easy to crank, more fuel less air.... when the air warms it moves the throttles actual flap opening wider, thus more air less fuel and harder starting, not as much fuel to combust and if the computer cannot sense the correct position, it will cause acceleration hesitating, poor idle, and what is called stumbling, where you press the gas and it kind of sounds like the motor sputters for a second and then goes or the occasional surging if at highway speed of say 60 mph and you feel the car kinda speed up mile or 2 and then back to the original speed.
My 93 nissan p/u had that issue, but the tps was replaced and it takes 2-3 revolutions on the motor and it's running smooth, hot or cold.
Hope this helps.
Mar 15, 2014 |
Cars & Trucks