C200 Throttle no response and idle up & down
Thread Starter
Newbie
Joined: Jun 2010
Posts: 12
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CLK320
C200 Throttle no response and idle up & down
Hi.
Currently my C200's idle is going up and down. Once I slightly press on the throttle pedal the idle will get even more aggressive up and down.
The throttle itself too has no response. No matter how i depress it the engine is not revving up.
Scanned with a MB Star, it has no fault.
What could have caused this ?
Currently my C200's idle is going up and down. Once I slightly press on the throttle pedal the idle will get even more aggressive up and down.
The throttle itself too has no response. No matter how i depress it the engine is not revving up.
Scanned with a MB Star, it has no fault.
What could have caused this ?
Junior Member
Joined: Feb 2012
Posts: 17
Likes: 0
1994 MB C220
Hi there! You must’ve solved your cars problem by now, but anyway I just want share my input according to my experience just recently. I think you basically have a MAF (Mass Air Flow Sensor) problem. Once broken it sends an erratic signal to the ECM/ECU which switches the system from open loop to close loop, and to the basic (limp mode) running configuration back and forth very rapidly until the fuel injectors and the ISC (throttle) actuators, the ignition, and the Cam adjuster has gone crazy following those instructions from the ECM.
Another one is TPS (Throttle position sensor); pointing to the potentiometer contact must’ve wear off, but it guess it won’t cause a violent up & down idling because of a perfectly good MAF is taking over the Air-fuel ratio all thru out the pedal movement. If you remove the MAF the engine could still run but in “limp mode” and drastically affect the fuel economy. It is actually comparable to a broken radio volume control. The last but not the least is the (frayed) ignition cables, (fouled) spark plugs, and weak ignition coil. You can also check on the O2 sensors can also cause a high or low (but stable) idling, and OVP relay box.
Another one is TPS (Throttle position sensor); pointing to the potentiometer contact must’ve wear off, but it guess it won’t cause a violent up & down idling because of a perfectly good MAF is taking over the Air-fuel ratio all thru out the pedal movement. If you remove the MAF the engine could still run but in “limp mode” and drastically affect the fuel economy. It is actually comparable to a broken radio volume control. The last but not the least is the (frayed) ignition cables, (fouled) spark plugs, and weak ignition coil. You can also check on the O2 sensors can also cause a high or low (but stable) idling, and OVP relay box.
