How camyou tell spark plug numbers on the distrubitor cap of a 1990 cadillac de ville?

The distributor cap of a 1990 Cadillac DeVille (and most other vehicles) won't have the spark plug numbers directly printed on it. Instead, the cap will have numbers (1, 2, 3, 4, 5, 6, 7, or 8 depending on the engine) that correspond to the firing order of the engine.

To find out which number on the distributor cap corresponds to which spark plug, you'll need to:

1. Consult your owner's manual: This is the best source. It will have a diagram showing the firing order and the corresponding spark plug locations.

2. Look for a diagram under the hood: Sometimes, manufacturers place a sticker under the hood, near the distributor, showing the firing order.

3. Use a repair manual: A Haynes or Chilton repair manual for your specific year and model Cadillac DeVille will have this information.

4. Online resources: Search online for "[Your Engine's Displacement] Cadillac DeVille firing order". (e.g., "4.5L Cadillac DeVille firing order") This will often reveal the firing order, which you can then use to match the numbers on the distributor cap to the spark plugs.

Important Note: The firing order is crucial. Connecting the wrong spark plug wire to the wrong terminal on the distributor cap can cause serious engine damage. Double and triple check your work before starting the engine.