hello my 400 sel with 178000 miles has been acting up lately. When i first turn it on, it idles at around 1100 rpm. After it warms up it idles around 6-700 rpm. These last few weeks it has begun to surge when in park. the rpm goes up and down from 100 to almost 1500rpm continuously until i put it into drive. it chokes for about 1 second when i first hit the gas but after that it runs smoothly. i have absolutely no clue what it can be. any help and recommendations is greatly appreciated.

 

change the distributor caps and rotors.... the computer is keeping it from cutting off... It will only get worse.... And eventually the computer won't be able to rev it up to compensate for the no electricity getting to the plugs problem.... and then it will just stall and be hard/impossible to start.... Good luck... Rotors and Caps from AUTOHAUZ @ $230 bucks.. New to this forum...

 

I have this problem with new distributors and rotors.

 

sounds like bad throttle body wires to me

 

Was afraid Of that. I have already replaced fuel injector harness. What part number should I look for? I have 1995 s420 with cruise control and ASR. I've looked and apparently there are a few different throttle bodies.

 

Just make sure it has your engine number on it,like mine is a m104, yours should 119. Ebay is a good place to look,and make sure its your engines years

 

So doesn't matter as long as it's for 92-95 for a 119?