1992 400se ASR/RPM problem
 

I have a 1992 400se. Last winter,cold starts would givve me a rush to 3000rpm's then back to 400rpm's then stall. This was the case until heat was achieved. Then it would start and run fine. Now when I start, it runs up to 4000rpm's and back to 400 rpm's and stalls. Sometimes upon restart, the ASR light will come on and it will idle fine but only 2/3 throttle. If you run the car like this, and do an ignition off/on, the ASR light goes out and the car will accelerate to 60mph by itself. Trickey getting it out of the garage when it does this. I try to get it in gear on the dropside of the rpm's but it wants to go by itself..good 10ft burn out marks on the floor!!!..what could be causing this?

I dont know, maybe vacuum, but the ASR light will come on in these cars in almost any fault situation. ASR itself is almost never the cause, the light is just a symptom.

You need to have codes read from the electronic accelerator computer.

I was driving home from Philly to Baltimore yesterday in my E500 and along the way, I braked to slow for a red light, which changed to green before I came to a stop. I took my foot off the brake and hit the gas and nothing happened. I pushed the gas further and looked at the IC and the ASR light was on. Then, suddenly, the car downshifted from 3rd to 1st, the revs shot up, and the car rocketed away. It continued to run with the first half of the accel. pedal range doing nothing and the tranny shifting like a drunk. I didn't want to stop because I had my four year old and four month old sleeping in the back (amazing they didn't wake up from the lurching, especially on the B-more Beltway at rush hour). But when I stopped and turned off and back on, the light was gone and car ran fine. Same thing this morning.

Question is, do the codes have to be read during the problem or can it still be dx'ed after the fact?

Both "willy" and "mark" have the symptoms of a (going) bad ETA.

First, get the codes read as MBDoc suggested; check Menu#24 on my MB page for the modules that you should "read".

Then let us know. . . .