Questions and Answers

Marquis Starts And Stalls Q. On a cold start my car starts right off but will not rev up. It stumbles along for 5-6 seconds then goes to a fast idle. Sometimes it stalls then it is okay the rest of the day. When the outside temperature drops down to below freezing the problem seems to go away. 1994 Mercury Marquis. 4.6 liter engine, 95,000 miles. New plugs, wires, coolant sensor.

A. It is possible you replaced the wrong Engine Coolant Temperature sensor (ECT). If you replaced the one on the right side of the engine, behind the alternator, you did. That one is for the temperature gauge in the car. You want the one in the left side, near the thermostat housing.

These symptoms are consistent with a bad ECT.

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