First, you MUST determine if your Suburban has a distributor. Look under the hood. If you see a round, black cap with wires coming out of it near the engine's front, and a rotor inside, you have a distributor. If you see individual ignition coils mounted directly on top of each spark plug, you have a COP system and this procedure doesn't apply. A COP system doesn't have a distributor cap to replace.
If you DO have a distributor:
1. Safety First: Disconnect the negative (-) battery cable to prevent accidental shorts.
2. Locate the Distributor Cap: It's usually located near the front of the engine, on top of the distributor.
3. Mark Wire Positions: Before removing the cap, carefully mark the position of each spark plug wire on the cap. You can use a marker or take a picture. Misplacing these wires will lead to misfires or engine damage. This is the most critical step.
4. Remove the Cap: Gently pull the cap straight up and off the distributor. There might be some resistance from the rotor button inside.
5. Inspect the Rotor: While you have the cap off, inspect the rotor. It should be free of cracks, carbon buildup, and excessive wear. Replace it if necessary.
6. Inspect the Distributor: Inspect the distributor for any cracks, damage, or excessive wear.
7. Install the New Cap: Align the new distributor cap with the rotor and push it firmly down until it snaps into place.
8. Reconnect the Spark Plug Wires: Connect the spark plug wires to the new cap, ensuring they are in the same position as they were originally, matching your markings.
9. Reconnect the Battery Cable: Reconnect the negative (-) battery cable.
10. Start the Engine: Start the engine and listen for any misfires. If the engine runs rough or misfires, you likely have a wire incorrectly connected. Recheck your connections and markings.
Important Considerations:
* Year and Engine: The exact procedure might vary slightly depending on the specific engine in your 1999 Suburban. Check your owner's manual for detailed instructions.
* Tools: You'll likely need only your hands to remove and install the cap, but having a flashlight might be helpful for better visibility.
* Professional Help: If you're not comfortable working on your vehicle, it's best to take it to a qualified mechanic. Incorrectly replacing the distributor cap can cause engine damage.
Remember, the vast majority of 1999 Suburbans use a COP ignition system, making this process irrelevant for most. Double-check your vehicle to confirm you have a distributor before attempting this repair.
