Idle Acceleration Stall W124

Hi All!

At my wits end. 1991 300CE with 111K. Gone over vehicle thoroughly replacing worn or suspect parts.............

Here is the situation:

Rough starting warm worse than cold.

Idles around 750 rpm with A/C on or off.

Main concern is stall condition from stop with A/C on. A/C cools fine.

The following items have been replaced in the last 5 months:

Plugs, rotor & cap
EHA valve
Cold Start Valve
OVP
Fan Clutch
All thermo sensors
O2 sensor
Fuel Filter

Any help would be greatly appreciated.

I have not checked the idle control valve yet.....but....how do you adjust the idle? I have adjusted the idle mixture to no avail. I cannot get the same readings with the a/c on as with the a/c off.

HELP!

John

[vutown]

jgmccahon,

Looking at all items you replaced, u missed the fuel injectors. Try those before trying more expensive parts. I wish I would of done that with my car. I went and replaced the fuel distributor ($600) before finding out that it was my injectors that were bad. Injectors only cost $25/each.



Hope this helps.


vu

[joel]

pour techron and drive somewhere far, and push
it really hard!!

[greenacres2]

PO had plats in our 560 which seemed rough to me but i had nothing to compare it to. After reading several plat vs Bosch copper threads here, changed plugs and car smoothed out a ton, especially at warm idle. Fuel mileage improved by about 1 mpg, which translated to about a 6 to 8 week payback.

Went through the platinum routine.......back to standard.

Problem exists only upon start-up or from full stop.

Runs great at any speed and idles fine.

Start-up problem gets worse when warm as time from shut-off increases, ie., 5 minutes OK but 45 minutes bad and 1 1/2 hours terrible.

Acceleration from full stop - engine stalls when punched (in other words no left turns unless there isn't a car for miles!)