Mazda 6 Service Manual: No.7 slow return to idle

No.6 cranks normally but will not start

No.8 engine runs rough/rolling idle

Other materials:

Mazda 6 Service Manual: Inspecting Electrolyte Level
A low level of electrolyte fluid will cause the battery to discharge quickly. Inspect the electrolyte level at least once a week. If it is low, remove the caps and add enough distilled water to bring the level between the upper and lower level (illustration). Do not overfill. Examine the sp ...

Mazda 6 Service Manual: Foreword
When the customer reports a vehicle malfunction, check the malfunction indicator lamp (MIL) indication and diagnostic trouble code (DTC), then diagnose the malfunction according to following flowchart. - If a DTC exists, diagnose the applicable DTC inspection. (See DTC TABLE.) - ...