My 240 has recently started hiccuping while I’m driving. Starts up absolutely fine. My idle is a little lower RPM than it usually has been, but no weird sounds. The problem begins when actually in motion. In each gear once I hit about 2300 rpms with my foot on the gas, the engine hiccups and jolts, slowing the car drastically. I lose throttle power until I depress the gas pedal again. It feels like there is a lot of tension pulling the car to slow down as this happens.
I believe it’s either an iat sensor or something along those lines but I wanted to see if anyone had any ideas. I just had the entire fuel system redone after a previous issue with a low idle and problems starting when the tank was below 3/4 full.
Let me know if you have any ideas or have had similar problems ! I’m relatively inexperienced as a mechanic but try to do as much of the work on my car on my own ! best wishes, thank you !

update ! throttle position sensor was faulty, replaced it, and back to driving smoothly !

 

the only 'sensor' in the idle circuit is the throttle position switch, which is a microswitch on the side of the throttle body that closes when the throttle plate is at idle, and is electrically open any other time.

the idle air controller is only activated when the throttle position switch indicates the throttle is completely closed (Idle) *AND* the RPMs drop below 700 RPM (or 1200 RPM with a cold engine).

potential causes of loss of power include things like inadequate fuel delivery, and an air leak in the air intake path between the MAF and the intake manifold. small air leaks tend to cause issues when idling, while larger ones that are intermittent can cause stumbling and power loss at higher speeds... worn engine mounts causing the engine to lean over more than normal can stretch the intake air plumbing opening up a crack to let in air.

 

thank you so much, I’ll check out your suggestions!