Could be your solenoid - there's three plugs (air pump, vdi, ssv) for the solenoids right behind the vac line - black blue and white iirc - I can't recall which one is the ssv - they plug into the solenoids that plug into the vac chamber - if the solenoid is bad, no vaccum goes to the vac actuator when it's powered. Although the actuator could be bad as well - I would try to get it tested with a vacuum hand pump if you can

Afrs would really help - it could also be clogged/leaky secondary injectors that start spraying when ssv opens

 

This picture shows the solenoids and yellow vacuum lines well

 

The SSV assembly which I believe included the impact switch and solenoid was replaced with no change.

Mazda tech diagnosis has concluded it to be a TCM (Transmission Control Module) Only problem is that it's their hunch based on the fact that their testing equipment loses signal at the hesitation point from the control module and the generic U0101 code (loss of communication with TCM)

This is $500 + $90 for the reprogramming.

I'm going to do some basic research but if anybody has further sources of information on this let me know.

Thanks

 

Just replaced the TCM and no longer get communication issues however, the 4k hesitation still exists.

 

Have you observed what your AFRs are doing during the hesitation yet?

 

No because it's been in the shop for a few weeks. I did try to take it to JBL but said they were busy until next week. Tried a couple other shops but no luck so I just turned it in.