ENGINE MECHANICAL - Engine Tune-up EM-9 TROUBLESHOOTING 5. (wi IDLE LIMITER CAP) INSTALL NEW IDLE LIMITER CAP After this adjustment is completed. install a new idle limiter cap on the mixture adjusting screw. CAUTION: After completing adjustment. perform a road test to make certain engine performance has not changed. EC0006 B. ALTERNATIVE METHOD To be used only if CO meter is not available. 1. VISUALLY INSPECT CARBURETOR (a) Check for loose screws or loose a mounting to the manifold . (b) Check for wear in the linkage. missing snap rings or excessive looseness in the throttle shaft. Correct any problems found . 2.
INITIAL CONDITIONS (a) Air cleaner installed (b) Normal operating coolant temperature (c) Choke fully open (e) All vacuum lines connected (d) All accessories switched off (f) Ignition timing set correctly (g) Transmission in the UN " range HC co Problems Causes High Normal Rough idle 1. Faulty ignition: • Incorrect timing • Fouled. shorted or improperly gapped plugs • Open or crossed ignition wires • Cracked distributor cap 2. Leaky exhaust valves 3. Leaky cylinder High Low Rough idle (Fluctuating HC reading) 1. Vacuum leak: • Vacuum hose • Intake manifold • PCV line • Carburetor base High High Rough idle (Black smoke from exhaust) 1. Restricted air filter 2. Plugged PCV valve 3.
Faulty carburetion: • Faulty choke action • Incorrect float setting • Leaking needle or seat • Leaking power valve