Throttle Body
CAUTION:
DO NOT adjust throttle valve stop screw as it is preset at factory.
NOTE:
Perform inspection only after engine has been warmed up to normal operating temperature (radiator fan comes on twice).
- Disconnect vacuum hose to purge canister at top of throttle body and connect vacuum gauge to throttle body. Start engine and warm-up to normal operating temperature. Ensure there is NO VACUUM.
- Check vacuum reading when throttle is opened slightly from idle. Stop engine and ensure throttle cable operates smoothly with binding or sticking. If any problems are found in steps 1) and 2), check for:
- Excessive wear or play in throttle valve shaft.
- Sticky or binding throttle valve lever at full close position.
- Clearance between throttle stop screw and throttle lever at full close position. There should be no clearance.
- Purge canister port should be located upstream of primary throttle valve in full closed position.