Infiniti Diagnostics Library
Think Nissan patterns with luxury packaging. Separate mixture control from misfire/mechanical, and prove EVAP influence before chasing fuel-pressure stories.
Platform notes (what actually helps)
- Misfire vs mixture: misfire + stable trims is usually ignition/mechanical; lean trims at idle often points to air leaks or purge influence.
- EVAP drivability: purge issues can cause long crank/rough restart after refuel. Treat it as unmetered air until proven otherwise.
- Cooling plausibility: thermostat/sensor bias can cause rich correction, poor economy and odd fan behaviour without obvious overheating.
- Don’t skip voltage checks: low voltage during cranking can create a “mess” of intermittent electronic complaints.
Start here (popular models)
Q50
Saloon baseline: trims-first workflow, misfire separation, and EVAP/cooling plausibility checks.
Open model →QX60
SUV baseline: intermittent warning triage, mixture vs misfire logic, and emissions plausibility without parts-darting.
Open model →Best workflow: read codes + freeze-frame, then log trims at idle and steady cruise. If trims are abnormal, prove leaks/purge first; if trims are stable, treat misfires as ignition/mechanical until proven otherwise.