1994 mitsubishi diamanta

to be the Mitsubishi guru

Ah, such kind words, and to elevated to guru status at last . I'll mention it to my sensei. But back to the problem at hand ...

There are several possibilities.

- check for cracked or broken vacuum tubes on the throttle body. Most likely problem to start with.

- is the CEL on, if so what error code(s) are being output?

- cold start is affected by the coolant temp sensor. Check that the connector/cable is not damaged, and that you have +5V (not +12) on one side and (0V orGND) on the other. The ECU may be reporting a sensor problem.

- the throttle body probably needs cleaning with one of the aerosol products. Can't hurt.

- the Idle Air Control motor on the throttle body may have damaged itself internally. There are some plastic gears that chew themselves up if the throttle body gets gummed up. Motor coils can also fail. Usually the ECU reports an error.

- check the timing

- check the throttle body adjustment for the idle speed. This is a large Phillips screw hidden in a tube structure on the top or side of the throttle body. There may still be a 10mm black cover over the screw. DO NOT adjust the external screw that sets the throttle closed. position.