2002 Mazda Millenia mazda millenia s surge and hesitation w

Actually, if it is worse after sitting for several days, I would lean toward an electrical / ignition problem. WHen was the vehicle last tuned up (including ignition wires)?

Service records unknown. I believe the coils are on top of the plugs so there are no iginition wires. Even when the car is warm I can feel a slight surge when it is warm and I am flooring it.

I have seen problems with the rubber boot that goes over the spark plug from the coil pack. They have gotten weak and have actually allowed spark to short out on the valve cover. (Actually arc through the boot)

You may want to check them. When this happens, there is usually a small gray spot on the boot where it arcs through.

As far as the fuel pump, you could check pressure after it sits for a few days. Here is the how to for checking:

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

If you need the gauge, many parts stores will lend or rent it.

Just drove this car again when it was cold and sitting for the day and it only hesitates under full throttle and will act normal at part throttle; it just happens when you floor it or half-way floor it. What do you think? Thanks, Dan

I REPLACED # 3 COIL AND PLUG,NOW I GET A P1173 CODE A/F MIXTURE CONTROLE(HO2S21) WHAT DO I NEED TO REPACE NOW OR WHERE SHOULD I BE LOOKIG
dAN