Mark X Rough Idle Stalling

Dear esteemed Toyota Mark X owner, I extend my felicitations and express my sincere concern regarding the tribulations you are encountering with your vehicle. The confluence of symptoms you delineate – namely, the rough engine running, the disconcerting engine stalls at idle, the illumination of the check engine light, and the unsettling jerking during acceleration – collectively intimates a potential anomaly within the ignition system. To ascertain the precise etiology of this matter, might I inquire whether you have undertaken any preliminary diagnostic assessments? Specifically, have you scrutinized the condition of the spark plugs, the integrity of the ignition coil wiring, and the functionality of the mass airflow sensor?

Thank you for your detailed response! I haven't checked the mass airflow sensor yet, but I did inspect the spark plugs and ignition coil wiring. They seemed okay visually, although I don't have the tools to test them thoroughly. What kind of diagnostic assessments would you recommend next, given that I don't have advanced equipment?

Esteemed Mark X proprietor, Given the limitations of your available diagnostic apparatus, and predicated upon the constellation of symptoms you have reported, it is my considered recommendation that you avail yourself of the services of a qualified automotive diagnostic facility. While a superficial visual inspection of the spark plugs and ignition coil wiring may not reveal latent defects, a professional technician, equipped with specialized diagnostic instrumentation, can perform a more exhaustive evaluation of the ignition system's constituent components. Furthermore, the presence of the check engine light suggests the presence of stored diagnostic trouble codes (DTCs), which can provide invaluable insights into the nature and location of the underlying fault. A diagnostic scan tool, wielded by a skilled technician, can readily retrieve these DTCs and facilitate a more targeted diagnostic approach. I suggest contacting a workshop to have the car properly diagnosed.

I appreciate your advice. I took it to a workshop, and indeed, it was a defective ignition coil due to a faulty connection. The repair cost me about 95€. Thanks again for your help!