No.11 Engine Stalls/Quits, Engine Runs Rough, Misses, Buck/Jerk, Hesitation/Stumble, Surges[L3 With Tc] - Mazda CX-7 2007 Workshop Manual

SYMPTOM TROUBLESHOOTING [L3 WITH TC]
STEP INSPECTION
13 Inspect the fuel pressure sensor.
(See01-40-35 FUEL PRESSURE SENSOR
INSPECTION[L3 WITH TC].)
Is the fuel pressure sensor normal?
14 Replace the high pressure fuel pump
Monitor FUEL_PRES PID.
Is the FUEL_PRES PID value within the
specified?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)
15 Connect the fuel pressure gauge between the
fuel pump and the high pressure fuel pump.
Measure the fuel pressure line of the low
pressure side.
(See01-14-5 FUEL LINE PRESSURE
INSPECTION[L3 WITH TC].)
Is the fuel pressure within the specification?
16 Inspect the fuel injector for each cylinder.
(See01-14-27 FUEL INJECTOR
INSPECTION[L3 WITH TC].)
Are fuel injectors normal?
17 Measure the compression pressure for each
cylinder.
(See01-10-9 COMPRESSION INSPECTION[L3
WITH TC].)
Are compression pressures within the
specification?
18 Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the
repair or diagnosis.
— If the vehicle is repaired, troubleshooting is completed.
— If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later
calibration is available. Retest.
End Of Sie
NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE,
SURGES[L3 WITH TC]
ENGINE STALLS/QUITS (ACCELERATION/CRUISE)
ENGINE RUNS ROUGH (ACCELERATION/CRUISE)
11 BUCK/JERK (ACCELERATION/CRUISE/DECELERATION)
HESITATION/STUMBLE (ACCELERATION)
SURGES (ACCELERATION/CRUISE)
• Engine stops unexpectedly at beginning of acceleration or during cruise.
• Engine stops unexpectedly while cruising.
• Engine speed fluctuates during acceleration or cruising.
• Engine misses during acceleration or cruising.
DESCRIPTION
• Vehicle bucks/jerks during acceleration, during or deceleration.
• Momentary pause at beginning of acceleration or during acceleration
• Momentary minor irregularity in engine output
RESULTS
Yes Go to Step 15.
No Replace the delivery pipe.
Yes Troubleshooting is completed.
Go to the Step 18.
No Go to the next step.
Yes Go to the next step.
No Inspect for the following:
• Fuel line restriction
• Fuel filter clogging
If normal replace the fuel pump.
Yes Go to the next step.
No Replace the suspected fuel injector.
(See01-14-23 FUEL INJECTOR REMOVAL/
INSTALLATION[L3 WITH TC].)
Yes Replace the injector driver module.
If the problem remains, overhaul the engine.
No Inspect for the following:
• Damaged valve seat
• Worn valve stem and valve guide
• Worn or stuck piston ring
• Worn piston, piston ring or cylinder
• Improper valve timing
Service if necessary.
ACTION
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