Diagnostic Procedure 7 — Hesitation when the Engine is Hot / Diagnostic Procedure 8 — Hesitation when the Engine is Cold
EF & EC-265flowchartApplies to GA16DE engine (header tag).
Diagnostic Procedure 7 — Hesitation when the Engine is Hot
1
1: CHECK FUEL VAPOR. 1. Disconnect fuel pressure regulator vacuum hose and plug hose. 2. Perform cruise test. 3. Does the hesitation disappear?
Yes
Check fuel properties.
No
2
2: CHECK FOR INTAKE AIR LEAK. When pinching blow-by hose (lowering the blow-by air supply), does the engine speed rise?
No
INSPECTION END
Yes
Discover air leak location and repair.
Diagnostic Procedure 8 — Hesitation when the Engine is Cold
1
1: CHECK SPARK PLUGS. Remove spark plugs and check for fouling, etc.
N.G.
Repair or replace spark plug(s).
O.K.
2
2: 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
3
3: TRY A KNOWN GOOD AIR FLOW METER.
Trouble is fixed.
Replace air flow meter.
Trouble is not fixed.
4
4: CHECK FOR INTAKE VALVE DEPOSITS. If there are deposits on intake valves, remove them.
INSPECTION END