Questions and Answers

Ford Mustang Check Engine Light Q. Good Sir; Help! My 1993 Ford Mustang. It has the 2.3 liter 4 Cylinder 2 coil pack 8 spark plug arrangement. The legendary and feared "Check Engine" light is now glaring at me. This vehicle has all power A/C, P/S, automatic transmission, and 98,000 miles on the clock.

I replaced the main computer about a year ago. I know there dozens of things that will make that light come to life. I tried to eliminate the simple stuff first. I changed the spark plugs. The radiator got a flush and thermostat change. As did the oil and filter. I checked to see if all the formed wiring harness were clipped together tightly. However to no avail. The check engine light steadfastly stays lit. With one exception. When I first start in the morning. The light may stay unlit for the first two to five minutes.

This also may help solve the mystery. When the Check Engine Light comes on, my tachometer will show only about half of my actual RPM from that point on. Thank you in advance for any time and effort you express on my behalf.

Respectfully,
Bill

A. I guess the first thing I would do is pull the codes from the computer. If the Check Engine Light (MIL) came on, the computer stored a code. Even if the MIL goes out, the code will remain stored in the computer.

You can get instructions on how to access the codes here: Trouble Shooting.