The service options you can perform on your Camry's ignition system depends on the model year. While you can't adjust the ignition timing on a distributorless ignition system, you can test the correct timing on a Camry made before 2002.
Get an after-market tachometer compatible with the Toyota Camry's ignition system.
Start up the Camry's engine and let it reach normal operating temperature.
Connect the tachometer tester probe to terminal IG of the Data Link Connector 1. Connect terminals TE1 and E1 of the DLC1 with a jumper connector.
Inspect the tachometer's timing. It should be between 8 and 12 degrees Before Top Dead Center. Set the timing as necessary.
Tighten the hold-down bolt and make sure the ignition timing advances.
Disconnect the negative terminal from the Camry's battery.
Remove the two nuts and clips on top of the cylinder head cover, then remove the cover. Disconnect the four ignition coil connectors and the bolts retaining the coils. You can now remove the coils.
Replace the coils as needed. Connect the bolts and coil connections and replace the cylinder head cover.
