High Engine Idle Speed

Check self-diagnostic system. Check output of diagnostic code. If codes are present, perform trouble shooting according to diagnostic codes. If codes are normal, check air suction from intake system.
If air suction is bad, check air entering intake system. If air suction from intake system is good, check throttle body. If throttle body is bad, check throttle body air valve for leaks.
If throttle body is good, check idle-up VSV. If idle-up VSV is bad, check idle-up VSV for leaks. If idle-up VSV is good, check A/C fast idle circuit.
If A/C fast idle circuit is bad, check A/C air valve for leaks. If A/C fast idle circuit is good, check PCV system. If PCV system is bad, check PCV valve for restriction and orifice.
If PCV system is good, check throttle position sensor. If throttle position sensor is bad, check throttle body. If throttle position sensor is good, check fuel pressure. Connect fuel pressure gauge to fuel line. Using Engine Control System Sub Harness (09991-87702-000), short terminal "F" (White/Black) to ground terminal (Black). See Figure .
Turn ignition on. Fuel pressure reading should be as specified in ENGINE TUNE-UP SPECIFICATIONS table. If fuel pressure is not within specification, check for fuel leaks, fuel pump fuse, fuel pump relay, fuel pump, fuel restriction, and fuel pressure regulator.
If fuel pressure is within specification, check CEC electronic circuit, using DVOM. See CEC SYSTEM DIAGNOSTICS under TESTING.