Q: Variable tumble control system, not really sure how to pinpoint what I need to do. Someone told me I need a new spark delay valve

There is a Mazda Technical Service Bulletin (TSB) involving the Variable Tumble Control System (VTCS) on your model. The issue in the TSB involved the mitigation of noise caused by the system and that mitigation involved re-programming of the controls. If that is the issue you are experiencing, obviously the applicability of the Mazda TSB should be considered first. What I would recommend is that you seek a diagnostic of the system to pinpoint the root cause of the malfunction that concerns you. To obtain that diagnostic, on a low cost, mobile basis, please use YourMechanic’s Check Engine Light diagnostic service request page and the responding certified mechanic will investigate and resolve the issue that you are writing in about. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.