SPN 1322 — Engine Misfire for Multiple Cylinders
System: Engine / Fuel
The engine computer has detected misfire on more than one cylinder, usually from uneven crankshaft speed between firing events.
Can I keep running it?
HIGH — limit use, diagnose now
Rough running under load can damage the engine and the DPF. Limit use until you know whether it is fuel supply, injectors or compression.
Likely causes
- Air in the fuel or low fuel supply pressure
- Worn, sticking or leaking injectors
- Low compression from rings or valves
- Contaminated fuel (water, wrong fuel)
- Injector wiring fault affecting a shared circuit
Checks & fixes (easiest first)
- Check fuel supply pressure and look for air with a clear line
- Read injector balance rates and run a cylinder cutout test
- Measure injector return flow
- Run a relative compression test
Common FMIs with SPN 1322
- SPN 1322 FMI 31Condition exists / not available
Related codes
- SPN 651Injector Cylinder #01
- SPN 157Injector Metering Rail 1 Pressure (Fuel Rail)
- SPN 94Fuel Delivery Pressure
Troubleshooting guides
FAQ
What does SPN 1322 mean?
SPN 1322 is Engine Misfire for Multiple Cylinders. The engine computer has detected misfire on more than one cylinder, usually from uneven crankshaft speed between firing events.
Can I keep running with SPN 1322?
Rough running under load can damage the engine and the DPF. Limit use until you know whether it is fuel supply, injectors or compression.
What causes SPN 1322?
Air in the fuel or low fuel supply pressure; Worn, sticking or leaking injectors; Low compression from rings or valves; Contaminated fuel (water, wrong fuel); Injector wiring fault affecting a shared circuit.