Tuning the Camry engine is a step-by-step maintenance procedure that is fairly straightforward. The most popular Camry engine is the 2.4 liter, 4 cylinder. It has a slant engine design that is very accessible for a tune up. Several items have changed about the Camry engine through the years, but not the basic design. Engine tuning has remained pretty constant for all year models, with the exception of the recent addition of a direct coil ignition.
Remove the spark plug wires and spark plugs. Read the plugs as they are removed from each cylinder. Look for fouling, oil spotting or excessive carbon buildup. Compare the plugs to each other. They should be uniform in appearance and wear. If one is different, the cylinder that plug represents could need additional repairs, and a tune up might not solve the problem.
Install new spark plugs and wires. Inspect each new plug and note if there is a significant difference in the electrode gap between them. Modern plugs are made to tight specifications and no gap adjustment should be necessary. If there is a big difference, refer to the gap specifications--which can usually be found on a label applied to the underside of the hood--and make the needed adjustment.
Apply anti-seize compound to the spark plug threads and install them. Apply boot release to each plug wire boot and install the wires. Do this one at a time to avoid wire mix-up.
The newer models will have four individual ignition coils mounted to the valve cover. These are held in place by bolts. Remove the bolts and unplug the coil. Lift directly up and the spark plug connector, attached to the coil, will come out as well. Replace the spark plugs, add boot release to the plug connector, and reinstall the coils.
Replace the air filter. Unclip the upper air filter housing and set it aside. Remove the air filter. Spray the inside of the housing with an aerosol dust remover and wipe the housing with a shop cloth. Install the new air filter.
Replace the fuel filter. Disconnect the battery to avoid accidental sparks and fire. Locate the fuel filter, traditionally mounted near or on the driver's side firewall. Place shop rags under the filter. The filter is under pressure, and gas will escape when the supply line bolts are loosened.
Loosen the bolts and remove them. Remove the filter mounting bolts. Set the old filter aside and install the new filter. The upper and lower hoses require two copper gaskets each. Install the new gaskets and install the upper and lower fuel line bolts.
