Smart Forfour Throttle Issues Impact Performance

Had similar issues with my Smart ForTwo (2017, gasoline) last summer. The symptoms match what I experienced, poor throttle response, rough engine idle, and inconsistent acceleration. The throttle position sensor was indeed faulty, but it was part of a larger issue with the throttle body assembly. When the mechanic inspected it, they found carbon buildup around the throttle valve, which prevented proper air-fuel mixture control. The repair involved: Cleaning the throttle body, Replacing the throttle position sensor, Recalibrating the control valve, Performing a computer reset This was a serious repair that required specialized diagnostic equipment. The throttle body is a critical component that manages air flow into the engine. When it malfunctions, it can cause various performance issues and potentially leave you stranded. The repair resolved all symptoms, smooth acceleration returned, fuel efficiency improved, and the engine idle stabilized. For this type of issue, choosing a shop with experience in electronic throttle systems is crucial. Since these symptoms can also indicate other problems, getting a proper diagnosis with diagnostic equipment is essential before replacing parts.

Thanks for sharing your experience. Your symptoms were exactly like mine. My throttle control issues got resolved with a similar fix. Quick question, do you remember the total repair cost? Also, has everything been running smoothly since the fix, or have you noticed any other engine idle or fuel efficiency issues? My car has been great for the past month since the repair, but I am still monitoring the throttle response closely.

The total repair came to 205€ for fixing the defective accelerator pedal module, which included the throttle valve replacement. Everything has been running perfectly since the fix, the engine idle is steady, and fuel efficiency is back to normal. The car throttle response is crisp and predictable now, much better than before. The mechanic confirmed that the air intake system is working as intended, and the control valve calibration they performed has eliminated all the previous issues. It has been about 6 months since the repair, and I have not experienced any recurring problems. The investment was worth it, as the car feels like new again. Just keep monitoring as you are doing, but based on my experience, once the throttle valve issue is properly fixed, it tends to stay fixed. The important thing is that the root cause was addressed rather than just treating symptoms.

After reading about similar experiences, I decided to take my Smart Forfour to a different mechanic who specializes in electronic throttle systems. The diagnosis confirmed what others suggested, carbon buildup around the throttle valve and a faulty throttle position sensor. The repair cost me 280€, which included throttle cleaning, sensor replacement, and control valve calibration. Since the fix three weeks ago, the fuel efficiency has improved dramatically. The engine starts smoothly now, and the throttle response feels much more precise. I am glad I addressed this issue promptly, as the mechanic mentioned it could have led to more serious problems. The new shop did excellent work, properly diagnosing and fixing the root cause rather than just treating symptoms. They even showed me the carbon buildup they cleaned from the throttle body. Will keep monitoring the performance, but so far, the car runs better than it has in months. Thanks to everyone who shared their experiences and helped point me in the right direction.