Diagnostic Procedure 3 — Unstable Idle (Cont'd)
EF & EC-432flowchartEXHAUST GAS SENSOR check applies to MODELS WITH CATALYZER ONLY.
Diagnostic Procedure 3 — Unstable Idle (Cont'd)
1
A
2
CHECK SPARK PLUGS. Remove the spark plugs and check for fouling, etc.
N.G.
Repair or replace spark plug(s).
O.K.
3
CHECK FUEL PRESSURE. 1. Release fuel pressure to zero. (Refer to page EF & EC-638.) 2. Install fuel pressure gauge and check fuel pressure. At idle: Approx. 245 kPa (2.45 bar, 2.5 kg/cm2, 36 psi)
N.G.
Check fuel pump and circuit.
O.K.
4
CHECK EXHAUST GAS SENSOR. (MODELS WITH CATALYZER ONLY) 1. See "M/R F/C MNT" in "Data monitor" mode. 2. Maintaining engine at 2,000 rpm under no-load (engine is warmed up sufficiently.), check 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 to make sure 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.
N.G.
Replace exhaust gas sensor.
O.K.
5
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