Really Scary (and Very Very Odd) Stalling Problem M103

[350SL4spd]

OK. The story first:
I was going down a country road the other day, not exceeding the speed limit (there wasn't one ) and came over a hill into a blind corner. I dug in the brakes and cranked the wheel over, ABS kicked in as it should (slightly gravely road) and then the car stalled . No more ABS or ability to try and regain traction by getting into the gas...spun out, but managed to keep it between the ditches. My immediate thought was that I was low on gas(reserve light had come on not half a mile before) and that the G force of the corner sloshed all the fuel to one side of the tank, stalling the car. But I talked to the PO (a good friend of mine) and he said that this had been a problem years ago. He even had it into the dealership a few times and they replaced several things (inc the EHA) but were flabbergasted.

The Question: Well, in discussing our experiences w/ this we came up with this senario: When coming into a corner at higher-than-average-G's (faster than one would on a daily basis, definitly spill-your-coffee-corner) and getting into the brake hard (maybe not until ABS kicks in but not too far away) the car just flat out stalls. I don't like this idea. It is there, at the ratty edge of control, that you need your car not to panic, and pull some very "Italian car" stunt like stalling (the same friends Alfa did that all the time...turn on the radio, car would stall ). WHAT THE HELL IS CAUSING THIS?? I think it has to be something electric, but I don't know where to look. Anyone had a similar prob? Every lose or almost lose control of your W124 and have it stall? Was there a recall about this I didn't know? I know the OVP is hooked into both systems (right?). What else is? I would really like to figure this out before I swerve to avoid a Girl Scout that is helping an old lady carring puppies across the street and I end up dead.

Thanks for any imput.

-Matt-

(ps: And don't tell me that the best solution is not to take corners so fast. This solution only works if you can also control what everyone else is doing too. )

(pps: The car is my well taken care of 1991 300E)

[chazola]

hope you used the emergency brake

mine did this a couple of times, low-speed, downhill. I took out the MAS, cleaned the contacts and put it back in. It hasn't stalled since.

[psfred]

The usual cause of a stall under hard braking is a sticky idle control valve, compounded most times by vacuum leaks, often at the idle control valve hoses.

If those two hoses leak more under sideways force, the problem will be worse.

The other possibility is a bad fuel pump relay, but that usually causes random stalls while driving before it quits all together.

You may have simply run it out of fuel, too, but cornering hard.

Peter

[350SL4spd]

Something just occured to me....Is there a mechanism in this model that would shut off fuel in case of an accident. I would find it hard to believe that there wouldn't be one... If there is one, it would make sense that under that combination of corner G and nose down force of braking (and only the combination) that an overly sensitive/broken fuel shut off might be tripped. Is there one in this model??? Where might it be found?
Thanks!
-Matt-

[stevebfl]

Fuel pump relay shuts off fuel when the engine dies (for any reason).

Stalling condition sounds a lot like a bad airflow pot. But it could be most anything.

[350SL4spd]

But, What is the thing that tells the FPR "Holy S***, the car is almost upside down, we'd better shut the fuel off!!" ?
Hmmm....maybe I had better get back into my wiring diagrams....
And also better check out MAS/air pot and check their operation.
Thanks guys, just don't need this to happen in a real emergency!
-Matt-

[ejsharp]

The first thing I would look at is the fuel relay. They tend to malfunction if there is a crack on the printed circuit board. Cracks commonly occur on the cack of the board where the component's pins are soldered to the boards circuits.

Open relay (Pull off top) and examine back of board with magnifying glass.

[rayhennig]

Originally Posted by 350SL4spd

better check out MAS

For clarity, the fuel pump relay is in the MAS box. As are other things.

RayH

[Duke2.6]

What gear/revs when you hit the brakes and did you push in the clutch at some point before the car came to rest?

Duke

[350SL4spd]

Resurrecting a 20yr old thread here. Almost on it's anniversary. Lol.

Car at the time was an M103 W124 Automatic. 1991 300E. Long since sold, but the problem was never sussed out.

For anyone else still having this problem or a similar one: When it did happen on that car it was likely in a higher gear before I pulled off the gas hard and started braking. It did happen more than once to me on that car.

[nulu]

In the past when quicky letting off the throttle and mercedes and other makes ive cleaned the throttle plate and solved stalling when slowing