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: General procedures
PRECAUTION (SUSPENSION) Wheels and Tires Removal/Installation When a wheel is installed, tighten it to 88-118 N·m {9.0-12.0 kgf·m, 65.0-87.0 ft·lbf}. Suspension Links Removal/Installation Tighten any part of the suspension that uses rubber bushings only after the vehicle has been lowered ...

Mazda 6 Service Manual: Mounting the Spare Tire
1. Remove dirt and grime from the mounting surfaces of the wheel and hub, including the hub bolts, with a cloth. WARNING Make sure the mounting surfaces of the wheel, hub and lug nuts are clean before changing or replacing tires: When changing or replacing a tire, not removing dirt and gri ...