Trouble Diagnoses — Diagnostic Procedure 3 — Unstable Idle (Cont'd)
EF & EC-257flowchartGA16DE engine. Idle spec given in kPa, bar, kg/cm2 and psi.
Diagnostic Procedure 3 — Unstable Idle (Cont'd)
1
A (from previous page)
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-353.) 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 FOR INTAKE AIR LEAK. When pinching blow-by hose (lowering the blow-by air supply), does the engine speed rise?
Yes
Discover air leak location and repair.
No
5
CHECK IDLE ADJ. SCREW CLOGGING. 1. Perform "IGN TIMING ADJ" in "WORK SUPPORT" mode. 2. Can you set engine rpm at 800 ± 50 rpm (in "N" position) by turning idle adjusting screw? -OR- 1. Disconnect throttle sensor harness connector. 2. Can you set engine rpm at 800 ± 50 rpm (in "N" position) by turning idle adjusting screw?
No
Check for IAS clogging or throttle valve clogging.
Yes
6
(Go to B on next page.)