Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, SURGES [BP, BP WITH TC] DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	Verify following: Vacuum connection ACL element No air leakage from intake-air system No restriction of intake-air system Proper sealing of intake manifold and components attached to intake manifold: (EGR valve, IAC valve) Ignition wiring Fuel quality: Proper octane, contamination, winter/summer blend Electrical connections Smooth operation of throttle valve Are all items okay?	Yes	Go to the next step.
1		No	Service if necessary and repeat Step 1.
2	Connect WDS or equivalent to DLC-2. Turn ignition switch to ON. Retrieve any DTC. Is "PASSED" displayed?	Yes	No DTC displayed: Go to the next step.
2		No	DTC displayed: Go to appropriate DTC test.
3	Is engine overheating?	Yes	Go to symptom troubleshooting No.17 "NO.17 COOLING SYSTEM CONCERNS-OVERHEATING ".
3	Is engine overheating?	No	Go to the next step.
4	Connect WDS or equivalent to DLC-2. Access RPM, MAF, TP, and VSS PIDs. Drive vehicle while monitoring PIDs. Are PIDs within specification? (See PCM INSPECTION )	Yes	Go to the next step.
4		No	RPM PID: Inspect CKP sensor and related harness; such as vibration, intermittent open/short circuit. MAF PID: Inspect for open circuit of MAF sensor and related wiring harness intermittently. TP PID: Inspect if output signal from TP sensor changes smoothly. VSS PID: Inspect for open circuit of VSS and related wiring harness intermittently.
5	Visually inspect CKP sensor and teeth of crankshaft pulley. Are CKP sensor and teeth of crankshaft pulley okay?	Yes	Go to the next step.
5		No	Replace malfunctioning parts.
6	Measure gap between CKP sensor and teeth of crankshaft pulley. Specification 0.5-1.5 mm {0.020-0.059 in} Is gap within specification?	Yes	Go to the next step.
6		No	Adjust CKP sensor.
7	Inspect spark plug conditions. Is spark plug wet, grayish white, or converted with carbon?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect for clogged fuel injector.
7		No	Install spark plugs on original cylinders. Go to the next step.
8	Remove and shake PCV valve. Does PCV valve rattle?	Yes	Go to the next step.
8	Remove and shake PCV valve. Does PCV valve rattle?	No	Replace PCV valve.
9	Verify that throttle lever is resting on throttle valve stop screw and/or throttle valve orifice plug. Is lever in correct position?	Yes	Go to the next step.
9		No	Adjust if necessary.
10	Are there restrictions in exhaust system?	Yes	Inspect exhaust system.
10	Are there restrictions in exhaust system?	No	Go to the next step.
11	Install fuel gauge between fuel filter and fuel distributor. Connect a jumper wire between terminal F/P at DLC in engine compartment and GND. Turn ignition switch to ON. Is fuel line pressure correct with ignition switch at ON? Fuel line pressure 370-420 kPa {3.7-4.3 kgf/cm2, 53-61 psi}	Yes	Go to the next step.
11		No	Zero or low: Inspect FP circuit Inspect for open FP relief valve Inspect for fuel leakage inside pressure regulator Inspect for clogged main fuel line Inspect pulsation damper High: Inspect pressure regulator for high pressure cause Inspect for clogged fuel return line
12	Visually inspect for fuel leakage at fuel injector O-ring, pulsation damper, and fuel line. Service if necessary. Is fuel line pressure fluctuation within specification after ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION )	Yes	Go to the next step.
12		No	Inspect pressure regulator diaphragm condition. If condition is okay, inspect fuel injector. If condition is not okay, replace pressure regulator.
13	NOTE: The following test is for engine stalling with A/C on. If other symptoms exist, go to the next step. Connect a pressure gauge to A/C low and high pressure side lines. Turn A/C on and measure low side and high side pressures. Are pressures within specifications? (See REFRIGERANT PRESSURE CHECK )	Yes	Go to the next step.
13		No	If A/C is always on, go to symptom troubleshooting No.24 "A/C ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY ". For other symptoms, inspect following: Refrigerant charging amount Condenser fan operation
14	NOTE: The following test is performed for symptom with cruise control ON. If other symptoms exist, go to the next step. Inspect cruise control system. Is cruise control system okay?	Yes	Go to the next step.
14		No	Repair or replace.
15	Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. Plug opening end of vacuum hose. Drive vehicle. Does engine condition improve?	Yes	Inspect if purge solenoid valve is stuck open mechanically. Inspect EVAP control system.
15		No	Go to the next step.
16	Visually inspect CMP sensor and teeth of camshaft pulley. Are CMP sensor and teeth of camshaft pulley okay?	Yes	Go to the next step.
16		No	Replace malfunctioning parts.
17	Inspect VTCS operation. (See VARIABLE TUMBLE CONTROL SYSTEM (VTCS) OPERATION INSPECTION ) Is VTCS okay?	Yes	Go to the next step.
17		No	Repair or replace malfunctioning parts.
18	Inspect EGR system. Is EGR system okay?	Yes	Go to the next step.
18	Inspect EGR system. Is EGR system okay?	No	Replace malfunctioning parts.
19	Is engine compression correct?	Yes	Inspect following: Valve timing Internal transmission part (AT only) Clutch (MT only)
19	Is engine compression correct?	No	Inspect for cause.
20	Verify test results. If okay, return to diagnostic index to service any additional symptoms. If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace PCM.