Idle 96 C220
 

All of a sudden, my C220 would not stay on idle. It starts fine but when I let off gass it dies. I wasn't sure what was causing it, I thought maybe bad gas so I added HEET last night. Started it this morning and it seems to stay on but barely. I drove around and seems to continue staying on.

I did spray the MAF with brake clean but that did not show any improvement.

If there is water in the tank, I'm hoping that it will continue to diminish. The tank is 3/4 full.

Wiring harness was also recently replaced with a new one.

Carbon build-up on the throttle butterfly can cause that issue,
try scrubbing with a Scotch-brite pad & then washing off with intake air cleaner.

Doc, this helped quite a bit. I just sprayed with intake cleaner but I'll go back in and scrub it this weekend.

Btw, what do you know of C320's. I'm looking at an 05. Apparently, these have the E320 engines? No wonder it was quite more peppy than a C280 or even a C230K.

But what about the rest of the car? Thanks