I have a 2005 MCS. I recently started experiencing loss of power. This happens when the car hits over 4000 rpm. Once this happens you can hear a sound coming from the air filter and it sounds as if the car is begging for air. I ended up taking off the hose that connects the air filter to the throttle body and noticed that the throttled body was no longer opening when stepping on the gas it just stayed shut. Shutting of the car and turning it back on made the throttle body to start working again but only for a short period of time before it stopped opening again. Can anyone tell me what my problem is? Is it the throttle body itself? Another sensor? Something else?

 

Sounds like ECM but stuff to check
1. Air - pull air filter and run it to 4k rpm
2. Fuel - check fuel pressure at the rail when at 4k rpm
3. Spark - replace plugs, coil, wires
4. Sensors - test/replace crank, cam


Finally - if no relief after all the above -ECM
https://www.northamericanmotoring.co...ing-rough.html


Good Luck
Bruce