During cold starts engine will not idle?

2003 TOYOTA CELICA
260,700 MILES • 1.8L • 4 CYL • 2WD • AUTOMATIC
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EDIAMAE
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RPMs slightly fluctuates, however will become idle and smooth out after 13 minutes once temperatures reach nominal level.

Another thing is that if gear selected to any gear range engine before engine reaching the normal temperature car will be jerky and hard to drive. Otherwise, you have to wait for the engine to idle before you make any gear select.

Car performs normal and good idle when its warm (normal operating temperature).
Aug 1, 2023 at 2:30 PM
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JACOBANDNICKOLAS
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Hi,

Since it does this cold, the first thing I suspect is the coolant temperature (ECT) sensor isn't sending the correct signal. The ECT is used by the PCM to determine the air-fuel mixture needed for the vehicle to run properly.

The colder the engine is, the more fuel it needs. Once it is at operating temperature, it needs less. So, what I would suggest is this. If you have a live data scan tool, before starting the car in the morning, check the signal from the ECT. It should be very close to the ambient temperature. If it is off by more than 10 degrees, replace the sensor.

If you look below, I attached two pics to help you locate the sensor.

Let me know if this helps or what you find.

Take care,

joe

See pics below.
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Aug 1, 2023 at 10:04 PM