Home Auto Repair How Do I Set the Timing on a 4.5L 90 Cadillac Coupe...

How Do I Set the Timing on a 4.5L 90 Cadillac Coupe Deville?


The 4.5-liter engine on a 1990 Cadillac Coupe DeVille has many different moving components, and all of them have to work together in harmony or else the engine won’t run. The process which helps everything to work correctly is called the ignition timing, and it needs to be very precise. If not, the engine will run poorly, if at all. When you need to adjust your timing, you can do so in less than an hour with a few tools.

Things You’ll Need: Timing light, 10-gauge wire, Wire cutters, Wire strippers, Open-end wrench set


  • Park the Cadillac and put on the parking brake. Open the hood and locate the number one spark plug wire, which is the furthest forward on the drivers side on the engine. Attach the clamp from the timing light to the number one spark plug wire.