Mazda 6 Service Manual: No.6 cranks normally but will not start

No.5 engine stalls-after start/at idle

No.7 slow return to idle

Other materials:

Mazda 6 Service Manual: Clutch master cylinder disassembly/assembly
1. Disassemble in the order indicated in the table. 2. Assemble in the reverse order of disassembly. Snap Ring Disassembly/Assembly Note Hold the piston down using a cloth-wrapped pin punch. If disassembling, remove the snap ring; if assembling, install it. ...

Mazda 6 Service Manual: Dual proportioning valve replacement (without abs)
1. Remove in the order indicated in the table. 2. Install in the reverse order of removal. Dual Proportioning Valve Installation Note Install the dual proportioning valve so that the R mark faces the left side of the vehicle. ...