1993 Mercury Grand Marquis Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 1993 Mercury Grand Marquis
1993 Mercury Grand Marquis Problems
The throttle position sensor (TPS) may fail. Common symptoms of a defective TPS can be rough idle, hard starting, hesitation on acceleration, poor fuel economy, and stalling.
The EGR valve position (EVP) sensor can fail on this vehicle. The EVP sensor measures the EGR valve position and transmits the date to the engine control computer. If it fails, drivability and fuel economy can suffer, the Check Engine Light will commonly illuminate.