Anonymous asked in Cars & TransportationCar MakesDodge · 9 years ago

Can any mechanics out there give me some more insight on a 97 Dodge 3.3 Intrepid?

My question is when a 3.3 96 Dodge engine when the car is cold started and it warms up to normal operating temperatures does the ECM calibrate a certain gas and air mixture that it uses when the car is driving at low and higher speeds? If the idle was too high when warmed up would the ECM also be going by this mixture when it's in gear and being driven and therefore you'd have a rich fuel mixture at any speed you drive at?

Thanx to all and Merry Xmas Happy New year

2 Answers

  • Favorite Answer

    The ECM "should" adjust the air/fuel ratio using input from various sensors, manifold absolute pressure (MAP), one or possibly more oxygen sensor(s) located in exhaust system, vehicle speed sensor (VSS), throttle position sensor (TPS), coolant temperature sensor, etc., any one of these giving an incomplete or incorrect input to the ECM can cause incorrect air/fuel ratio.

    The throttle position sensor will cause unusual idle speeds and sometimes stalling regardless of throttle position if the sensor is not registering actual throttle blade position. The TPS sends throttle position as an electrical signal to the ECM. i.e. If you are sitting stopped at a traffic signal with the car in gear, your foot off the accelerator and the tachometer is registering 1500 RPM, the TPS may be malfunctioning.

    Source(s): Forty five years of shadetree engineering, racing, and home auto repair, all Mopars, mostly Dodges.
  • Anonymous
    9 years ago

    you would have a richer mix when cold so that the engine runs smoothly and does not stall. the engine runs at its most economic when its at normal operating temperatures.

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