How to Set the Timing on a 1991 Toyota Camryby Nak Bhat
The ignition timing for an engine dictates when a spark is fired to ignite fuel in the combustion chamber. This timing has to be set properly to fully utilize the energy released by the combustion of fuel. If a spark is fired too early or too late, then all the fuel being injected is not utilized and goes to waste. Bad timing also affects the emissions from an engine. Adjusting the timing on a 1991 Toyota Camry requires a few tools and some precise mechanical adjustments.
Start the vehicle and let it get to normal operating temperature.
Pop the hood of your 1991 Camry. [Connect a tachometer](https://itstillruns.com/connect-tachometer-4857142.html) test probe to the distributor terminal connector located on top of the distributor.
Use a small service wire to connect terminals "TE1" and "E1" on the check connector.
Run the engine between 1,000 and 1,400 RPM for 10 seconds then let it return to idle. The idle RPM should be approximately 700 RPM.
Attach the timing light to the vehicle by connecting the black clip to the negative terminal on the car battery and the red clip to the positive terminal.
Connect the timing wire to a spark plug wire for cylinder #1, the one closest to the belts and pulleys on the front of the vehicle.
Use the timing light by pressing the trigger and aiming at the timing mark chart on the engine to make sure that the timing mark on the timing cover is aligned with the mark on the crankshaft pulley. Ignition timing at idle should be at 10 degrees Below Top Dead Center (BTDC).
Rotate the distributor housing and tighten the distributor bolt using a wrench of the appropriate size and recheck the timing if it is not 10 degrees BTDC.
Remove the service wire and check the idle advance timing. This should be between 13 and 22 degrees BTDC at idle. Make any adjustments with the distributor bolt if necessary.
Disconnect the timing light and service wire when the ignition timing is set to the desired specifications.
- Do not let the tachometer lead touch ground as doing so may damage the ignition coil.
Items you will need
- Timing light
- Service wire
- "All Data Repair Guide"; Alldata; 2008
- Aeronautical piston engine image by Andrew Breeden from Fotolia.com