What is spark plug gap for 1989 Mercury Topaz?
gap them at .54 I have a 1993 Mercury Topaz with the 2.3 Liter I-4. The recommended gap is .044 (44 thousandths). I highly doubt that the plug will fire with just over 1/2 gap as recommended earlier. The correct gap should be listed on the emissions label under the hood. I have a 1993 Topaz with the 3.0L V6 and the label on my car is on the body piece in front of the radiator. Mine listed a recommended 0.042" - 0.046" gap. I have mine set at 0.044"
1987, if early edition most likely carb. Spark plug gap should be 0.044. The change was in 1989 going to 0.054 inch. If you ever have a problem that the car just stalls, and will re-start several minutes later, and happens often or once in awhile, change the module on the firewall, sort of like a silver box with 1 wire harness plugged into it. They have a tendency to short out. good luck.