I have a '89 190E 2.6 Auto that stalls when coming to a stop. It used to do
it once in a while like once every month, however, now it does it at least
once a day. It doesn't seem to do it in the first 5 miles I drive but I can't confirm that.

Some suggestions that I read previously were the TDC Sensor, O2 Sensor, Over voltage protection relay
and some others I can't remember. Did anyone who had this problem ever get it
corrected and what was the actual problem.

Any help would be greatly appreciated!

If it restarts pretty much immediately after stalling, it's probably the fuel pump relay. If you listen VERY carefully toward the rear of the vehicle right when it stalls, you probably won't hear the fuel pump humming (like it does when you first turn the key to start it.) The relay is under the plastic shield behind the battery.

Thank You and you are correct in assuming that yes it does restart normally after it stalls. I will check the relay. Is this a common problem with this vehicle?

Yes, but It will usually die at weird times not just at idle. Does the car idle a little low all of the time? There is an idle modification that was on the Mercedes Red Fische that allowed for increased RPM while in gear. Also I have seen water in the connector for the CIS-E control unit. And I have seen the speed sensor faulty on the back of the speedo...My advise take it to a pro that knows these cars!!

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

It only stalls when coming to a stop. If the car is already stopped and is still running, it doesn't stall. As for the idle, it idles around 600rpm

I'm taking it to a dealer on Friday. I wanted some opinions and background on possible problems before then.

Your problem isn't easy to diagnose, but one of the most common failures is the air flow sensor. This sensor is attached to the housing below the fuel distributor & isn't available as a spare part. The complete housing must be replaced, so it can cost a few $$$$.

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MERCEDES BENZ MASTER GUILD TECHNICIAN
ASE MASTER TECHNICIAN
27 YEARS M.B. TECH

My car hasn't stalled the last couple of days. The outside temperature has been cooler. Is this a coincidence or is it related to my problem.

Hello,

As the weather has become warmer, I have noticed more postings about stalling vehicles, particularly W124s. I too am having this problem and hope you all can help me zero in on the cause.

I have a 1989 260E that was on excellent behavior when I bought it this winter, but as soon as it got warm (DC-Metro area) it regularly stalls on startup and at idle, when in gear. (It never stalls when in neutral or park.)

These are my observations:

1. The stalling only occurs when the temperature is above 70 degrees according to LCD thermometer in dash.

2. On initial startup, the engine will rev until I let go of the key. Then it will drop to zero and stop. I have to restart about three or four times before the car will idle at about 400-500 rpm (I did not think it could idle at such low speed). Usually, the ABS light will remain on.

3. If I depress the accelerator while starting, the engine will not lose power and stop, but the ABS light will remain lit. On one or two occasions, the light went off when I was idling after startup and the engine raced to about 1000-1500 rpm, then dropped to zero and shut off.

4. After driving for a while, the ABS light will go off.

The problem is obviously electrical in nature. The fuel pump is not getting enough power/voltage to maintain an adequate flow of fuel, and the engine is stalling.

The fact that the car did not behave like this in the winter indicates that the problem is heat related. But it is not the outside temperature that is the culprit, but rather the INSIDE temperature of the car. I know this because recently I ran the air conditioner for an extended time and after it got nice and cool in the car, the ABS light went off and the car did not stall again. Not surprisingly, the one or two times the car stalled in cold weather was when I had been driving for some time and the heater was on at full power.

I am no mechanic, but my educated guess is that an electronic component, i.e. over-voltage relay, fuel pump relay or other devices, is being affected by the interior cabin temperature. Perhaps an old or defective resistor (which becomes more resistant when heated and less resistant when cooled) in some electronic circuit is causing this problem, and choking the voltage to the fuel pump.

I have not taken the car to my mechanic yet, but before I do I'd be happy to know if anyone else has made these same observations.

Eric Silver
1989 260E

I'd bet if you replace the over voltage relay your problems will be solved. Also, take the connector off of the CIS-E control unit and spray it with contact cleaner and apply electrical grease to the terminals.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Are you refering to Eric's problem or my problem?

What's the CIS-E control unit?

Well my car stalled again this morning. In response to Eric's observations, it was still pretty cool (12C/54F) this morning, probably more so than the past few days. I didn't have my heater on or any vents open, just the sunroof.

I was replying to Eric's problem...The CIS control unit is the module responsible for the electronic engine management. If you don't know what it is you need to take your car to a tech.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Frank, have you had the coolant temp sensor checked? The air plate sensor will also cause this. (per MB DOC and me)

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Well I was at the dealer this morning and they told me that the O2 sensor isn't working. I didn't have it replaced yet so I can't tell you how it runs until next week. They had something hooked up (looks something like an analog volt meter) to the lambda sensor and it was showing 10 where is should have been fluctuating around 4 to 5.