Misfire In Several Cylinders
Misfire in several cylinders
Checking compression
- Remove all the spark plugs.
- Carry out a compression test according to Compression test Compression Test.
Is compression correct?
Yes - Checking cooling system
No - Replacing component
Remedy as necessary, then replace all spark plugs. It is vital that the correct spark plugs are used, see parts catalogue for P/N. Check the spark gap of new plugs before they are fitted. Spark gap should be 0.7 - 0.8 mm. Then continue with Fault-tracing information.
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Replacing component
- Remedy as necessary, then replace all spark plugs.
Note! It is vital that the correct spark plugs are used, see parts catalogue for P/N. Check the spark gap of new plugs before they are fitted. Spark gap should be 0.7 - 0.8 mm.
Continue - FAULT FOUND
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Checking cooling system
- Connect pressure tester 998 5496 ENGINE COOLANT SYSTEM - PRESSURE TESTER 998 5496 Engine Coolant System - Pressure Tester to the expansion tank.
- Pump up a pressure of approximately 100 kPa.
Shine a flashlight into each cylinder and check that there is no leakage between the cooling system and the cylinder.
Was there a leak?
Yes - Replacing component
Remedy as necessary, then replace all spark plugs. It is vital that the correct spark plugs are used, see parts catalogue for P/N. Check the spark gap of new plugs before they are fitted. Spark gap should be 0.7 - 0.8 mm. Then continue with Fault-tracing information.
No - Checking ignition cables
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Checking ignition cables
- Remove all ignition cables.
- Check the ignition cables for damage, cracks or arcing.
Then measure the resistance in each ignition cable. Resistance should be 1.5 - 4.5 kohms depending on their length, at 20°C.
Are any of the ignition cables damaged or do any have incorrect resistance?
Yes - Replacing component
No - Checking distributor cap and rotor
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Replacing component
- Replace ignition cables that are damaged or have an incorrect resistance.
- Check between ignition cables and distributor cap, spark plugs and ignition coil for loose connections.
Continue - Checking distributor cap and rotor
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Checking distributor cap and rotor
- Remove distributor cap.
- Check distributor cap/rotor for damage, cracks and flashover.
- If a fault is suspected: Clean. Replace suspect components if necessary.
Continue - Checking ignition coil primary winding
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Checking ignition coil primary winding
- Ignition off.
- Disconnect cable terminal from ignition coil terminal 15.
Connect an ohmmeter between two primary winding terminals (1 and 15).
The ohmmeter should read 0.5 - 1.5 ohms at +20 °C.
OK - Checking ignition coil secondary winding
Not OK - try a new ignition coil. Then continue with Checking voltage drop.
Replacing component
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Replacing component
- try a new ignition coil.
Continue - Checking voltage drop
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Checking ignition coil secondary winding
- Ignition off.
- Disconnect ignition coil HT lead.
Connect an ohmmeter between ignition coil terminal 15 and HT terminal.
The ohmmeter should read 8 - 9 kohms at +20°C.
OK - Checking voltage drop
Not OK - try a new ignition coil. Then continue with Checking voltage drop.
Replacing component
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Checking voltage drop
- Install new spark plugs.
Caution! It is vital that the correct spark plugs are used, see parts catalogue for P/N. Check the spark gap of new plugs before they are fitted. Spark gap should be 0.7 - 0.8 mm.
- Install distributor cap and connect all ignition cables.
- Connect cable terminal to ignition coil.
- Start the engine and idle it.
Connect a voltmeter between ignition coil terminal 15 and ground.
The voltmeter should read battery voltage.
OK - Checking ignition discharge module (IDM) ground terminal
Not OK - Checking for loose connections, contact resistance and oxidation
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Checking for loose connections, contact resistance and oxidation
- Check power supply terminals on central electrical unit, relay 2/31 and battery positive terminal for loose connections according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults and contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Checking ignition discharge module (IDM) ground terminal
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Checking ignition discharge module (IDM) ground terminal
- Ignition off.
- Wait for approximately 150 seconds (cars with immobilizer 245 seconds).
- Disconnect ignition discharge module (IDM).
Connect an ohmmeter between ignition discharge module (IDM) connector terminal 1 and ground.
The ohmmeter should read approximately 0 ohms.
OK - Checking ignition discharge module (IDM) cables and terminals
Not OK - Checking for contact resistance and oxidation
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Checking for contact resistance and oxidation
- Check ignition discharge module (IDM) ground terminal 31/52 for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Checking ignition discharge module (IDM) cables and terminals
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Checking ignition discharge module (IDM) cables and terminals
- Check cables between the following components for an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , an intermittent short-circuit to ground according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , and an intermittent short-circuit to supply voltage according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- ignition discharge module (IDM) terminal 4 and engine control module (ECM) #B11
- ignition discharge module (IDM) terminal 1 and ground terminal 31/52
- ignition discharge module (IDM) terminal 3 and battery positive terminal
- Check the following terminals for loose connections according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults and contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- ignition discharge module (IDM)
- engine control module (ECM)
- central electrical unit.
- relay 2/31
- battery positive terminal
- ground terminal 31/52
- Remedy if necessary.
Continue - Verification
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Checking flywheel/pulse wheel
- Start the engine and idle it.
- Select Volvo Scan Tool (ST) to read off the values for flywheel adaption B, C, D and E.
Values should be between -0.39 and +0.387.
OK - Checking injector power supply
Not OK - Check engine speed (RPM) sensor probe and the hole to the flywheel/carrier plate for damage, scratches and swarf. If the engine speed (RPM) sensor and hole are OK: Try a new flywheel, reset adaption. Then continue with Fault-tracing information.
Checking for damage
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Checking for damage
- Check engine speed (RPM) sensor probe and the hole to the flywheel/carrier plate for damage, scratches and swarf. If the engine speed (RPM) sensor and hole are OK: Try a new flywheel, reset adaption.
Continue - FAULT FOUND
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Checking injector power supply
- Check cables between injector terminal 1 and main relay (2/32) terminal 3 and engine control module (ECM) #A41 and main relay (2/32) terminal 1 for an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- Check injector, main relay (2/32) and engine control module (ECM) terminals for loose connections according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults and contact resistance and oxidation according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Continue - Checking fuel pump (FP) cables and terminals
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Checking fuel pump (FP) cables and terminals
- Check cables between the following components for an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , an intermittent short-circuit to ground according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , and an intermittent short-circuit to supply voltage according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- engine control module (ECM) #B27 and fuel pump (FP) relay terminal 4.
- fuel pump (FP) relay terminal 2 and ground terminal 31/51.
- battery positive terminal and fuel pump (FP) relay terminal 1.
- fuel pump (FP) relay terminal 3 and fuel pump (FP) terminal 1.
- fuel pump (FP) terminal 2 and ground terminal 31/48.
- Check terminals on the following components for loose connections according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults and contact resistance and oxidation according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- engine control module (ECM)
- fuel pump (FP) relay.
- ground terminal 31/51
- central electrical unit.
- relay 2/31
- battery positive terminal
- connectors 24/2 and 24/4.
- fuel pump (FP) connector C/BA and ground terminal 31/48.
Continue - Checking for air leakage
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Checking for air leakage
Check for air leakage according to Check for air leaks in the intake system Air Leaks In the Intake System, Checking.
Remedy as necessary.
Continue - Checking engine oil level
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Checking engine oil level
- Ignition off.
- Check engine oil level.
The oil level should be between the MIN and MAX marks.
OK - Checking fuel and residual pressures
Check fuel and residual pressure according to Check for air leaks in the intake system Air Leaks In the Intake System, Checking Checking for air leakage in the exhaust system Checking for Air Leakage In the Exhaust System.
Not OK - Ensuring correct oil level
Ensure that the oil level is correct. Then check fuel and residual pressure according to Check for air leaks in the intake system Air Leaks In the Intake System, Checking Checking for air leakage in the exhaust system Checking for Air Leakage In the Exhaust System.
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Checking fuel and residual pressures
- Check fuel and residual pressure according to Check for air leaks in the intake system Air Leaks In the Intake System, Checking Checking for air leakage in the exhaust system Checking for Air Leakage In the Exhaust System.
Continue - Fault-tracing information
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Ensuring correct oil level
- Ensure that the oil level is correct.
Continue - Fault-tracing information
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Fault-tracing information
Information
Fault-tracing information
In case of this defect, troubleshooting is not followed by verification.
The information can be displayed again or the fault-tracing for this fault can be interrupted.
Do you want to view the information again?
Yes - Attempt New Test
No - FAULT FOUND
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Attempt New Test - Checking compression
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