Mazda 6 Service Manual: No.4 hard to start/long crank/erratic start/erratic crank

No.3 will not crank

No.5 engine stalls-after start/at idle

Other materials:

Mazda 6 Service Manual: Foreword
Caution When the engine does not start or stalls and the following DTCs are not indicated, go to engine symptom troubleshooting. Note When the immobilizer system is defective, the engine cannot be started. If engine condition is normal but light stays on, inspect for short circ ...

Mazda 6 Service Manual: Recommendations for Shifting
Upshifting For normal acceleration and cruising, Mazda recommends these shift points: *1 Always observe local speed limit regulations. Downshifting When you must slow down in heavy traffic or on a steep upgrade, downshift before the engine starts to overwork. This gives better acceleration w ...