Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Does engine knock/ping/detonate?	Yes	Go to the symptom troubleshooting "No. 13 Knocking/pinging/detonation-Acceleration/cruise". (See NO.13 KNOCKING/PINGING/DETONATION-ACCELERATION/CRUISE .)
1	Does engine knock/ping/detonate?	No	Go to the next step.
2	Inspect for the following: Vacuum leak Proper fuel quality (e.g. proper octane, contamination, winter/summer blend) Blockage at intake-air system (between MAF sensor and intake ports) Loose bands on intake-air system hoses Cracks in intake-air system Air cleaner restriction Jet air mixing system air passage (clogging or leakage) MAF sensor installation Are all the items normal?	Yes	Go to the next step.
2		No	Service if necessary. Repeat Step 2.
3	Connect the WDS or equivalent to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
3		No	Go to the next step.
4	Connect the WDS or equivalent to the DLC-2. Access the ECT PID. Inspect the readings on both the ECT PID and the temperature gauge on the instrument cluster readings. Does the ECT PID indicate the same temperature as the gauge readings?	Yes	Go to the next step.
4		No	If temperature gauge is in the normal range but the ECT PID is not the same as the temperature gauge reading, inspect the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .) If the temperature gauge on instrument cluster indicates the cold range but the ECT PID is normal, inspect the temperature gauge and the sending unit. (See WATER TEMPERATURE GAUGE .)
5	Is the engine overheating?	Yes	Go to the symptom troubleshooting "No. 17 Cooling system concerns - Overheating". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING .)
5	Is the engine overheating?	No	Go to the next step.
6	Inspect for cracks on high-tension leads. Are there any cracks on high-tension leads?	Yes	Repair suspected high-tension leads.
6		No	Go to the next step.
7	Inspect the spark plug conditions. Is the spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: Inspect for fuel leakage from fuel injector. Spark plug is grayish white: Inspect for clogging fuel injector (FP1) (RP1).
7		No	Install spark plugs in the original positions. Go to the next step.
8	Visually inspect the eccentric shaft position sensor and the teeth of the pulse wheel. Are the eccentric shaft position sensor and the teeth of the pulse wheel normal?	Yes	Go to the next step.
8		No	Replace the malfunctioning parts.
9	Attempt to start the engine at part throttle. Does the engine run smoothly at part throttle?	Yes	Inspect the drive-by-wire control system operation. (See DRIVE-BY-WIRE CONTROL SYSTEM INSPECTION .)
9		No	Go to the next step.
10	Disconnect the fuel line quick release connector and install the fuel gauge to the fuel line. Short check connector terminal F/P to the body GND using a jumper wire. Turn the ignition switch to the ON position. Is the fuel line pressure correct with the ignition switch ON? (See FUEL LINE PRESSURE INSPECTION .)	Yes	Go to the next step.
10		No	Zero or low: Inspect the fuel pump relay and the fuel pump circuit. Inspect for clogged fuel line. If normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION .) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION .)
11	Is the fuel line pressure held after the ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION .)	Yes	Go to the next step.
11		No	Inspect the fuel injector. (See FUEL INJECTOR INSPECTION .) If the fuel injector is normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION .)
12	Disconnect the vacuum hose from the purge solenoid valve and plug the opening end of the vacuum hose. Attempt to start the engine. Is the starting condition improved?	Yes	Inspect if the purge solenoid valve sticks open.
12		No	Go to the next step.
13	Inspect the MAF sensor for contamination. Is there any contamination?	Yes	Replace the MAF sensor. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION .)
13		No	Go to the next step.
14	Visually inspect the exhaust system part. Is there any deformed exhaust system part?	Yes	Replace the suspected part.
14		No	Go to the next step.
15	Inspect the starting system. (See STARTER INSPECTION .) Is the starting system normal?	Yes	Go to the next step.
15		No	Repair or replace components if required.
16	Inspect the engine compression. (See COMPRESSION INSPECTION .) Is it normal?	Yes	Go to Step 21.
16		No	Go to the next step.
17	Perform the metering oil pump control inspection. (See METERING OIL PUMP CONTROL INSPECTION .) Does the metering oil pump control operate properly?	Yes	Go to the next step.
17		No	Repair or replace the malfunctioning part according to inspection results. After that overhaul or replace the engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .)
18	Check the engine oil condition. Is the engine oil low viscosity and/or is there a gasoline odor?	Yes	Replace the engine oil. Inspect the ECT sensor and the related wiring harnesses. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .) After that overhaul or replace the engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .)
18		No	Go to the next step.
19	Turn the ignition switch off. Disconnect the fuel line quick release connector and install the fuel gauge to the fuel line. NOTE: If the engine won't start, inspect the fuel line pressure with the ignition switch ON while cranking. Start the engine and run it at idle. Measure the fuel line pressure at idle. Is the fuel line pressure correct at idle? (See FUEL LINE PRESSURE INSPECTION .)	Yes	Go to the next step.
19		No	Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION .) After that overhaul or replace the engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .)
20	Check the oil pipe between the metering oil pump and the metering oil nozzle. Is there air and/or clogging in oil pipe?	Yes	Inspect and repair for leakage and/or clogging in the oil passage at the engine. After that overhaul or replace the engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .)
20		No	Overhaul or replace the engine. (See ENGINE REMOVAL/INSTALLATION or OVERHAUL - 1.3L (13B-MSB) .)
21	Check the oil pipe between the metering oil pump and the metering oil nozzle. Is there air and/or clogging in oil pipe?	Yes	Inspect and repair for leakage and/or clogging in the oil passage at the engine.
21		No	Go to the next step.
22	Perform the fuel injector operation inspection. (See FUEL INJECTOR OPERATION INSPECTION .) Does fuel injector operate properly?	Yes	Go to the next step.
22		No	Repair or replace the malfunctioning part according to the inspection results.
23	Inspect the fuel injectors for the following: (See FUEL INJECTOR INSPECTION .) Leakage Clogging Injector amount Are the injectors normal?	Yes	Inspect the engine oil condition (viscosity, amount deterioration).
23		No	Replace the suspected fuel injector.
24	Verify test results. If normal, return to the diagnostic index to service any additional symptoms. If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the repair or diagnosis.
*: 13B-MSP (High Power)