Diagnostic Procedure 9 — Hesitation under Normal Conditions

CHECK SPARK PLUGS. Remove spark plugs and check for fouling, etc.

CHECK EXHAUST GAS SENSOR. 1. See "M/R F/C MNT" in "DATA MONITOR" mode. 2. Maintaining engine at 2,000 rpm under no-load (with engine warmed up sufficiently), check to make sure that the monitor fluctuates between "LEAN" and "RICH" more than 5 times during 10 seconds. RICH→LEAN→RICH→ 1 time / 2 times → LEAN→RICH→ — OR — 1. Set "Exhaust gas sensor monitor" in the self-diagnostic Mode II. (See page EF & EC-412.) 2. Maintaining engine at 2,000 rpm under no-load, check that the RED L.E.D. on the E.C.U. or the check engine light on the instrument panel goes ON and OFF more than 5 times during 10 seconds.

CHECK FOR INTAKE AIR LEAK. When pinching blow-by hose (lowering the blow-by air supply), does the engine speed rise?