Questions and Answers
Toyota Tercel Has A Very High Idle
Q. I have a 1990 Toyota Tercel with a carburetor. The idle keeps going up. I turned it all the way down and it keeps getting higher, around 2,000 RPM. Can't find any vacuum leaks. Any suggestions?
A. The first thing you should do is check the computer for any stored codes. Here's how to do it.
EXTRACTING DIAGNOSTIC CODES:
- Confirm initial conditions:
- Battery voltage is at least 11 volts.
- Throttle valve is fully closed.
- Transmission is in neutral.
- All accessories turned OFF.
- Turn ignition switch ON, but DO NOT start engine.
- Connect a service wire across terminals T and E1 of the engine check connector.
- Read the diagnostic code(s) as indicated by the number of flashes of the "CHECK ENGINE" light on the instrument cluster.
- After codes are extracted, turn-off ignition switch and remove service wire.
DIAGNOSIS INDICATION If no malfunction codes are stored in the ECU, the "CHECK ENGINE" light will flash ON and OFF two times per second repeatedly. In the event of a malfunction, the light will flash every 0.5 second to indicate the first digit of the diagnostic code. This will be followed by a 1.5 second pause and 0.5 second flashes to indicate the second digit of the code.
If there are two or more codes stored in memory, there will be a 2.5 second pause between each code. After all the codes have been displayed, there will be a 4.5 second pause before the codes will be repeated in the same order. This sequence will continue as long as the check connector terminals remain shorted.
In the event that multiple codes are stored, the codes will display in numerical ascending order, with the lowest numbered code displayed first. All codes are retained in the ECU memory, until they are canceled using the proper procedure.
Once we know what the codes are, we can go from there.
If there are no codes and you are sure there are no vacuum leaks, then you're probably looking at a bad carburetor.
Additional Information provided courtesy of AllDATA
