1991 300e Stalling
 

I have a 91 300e. Start it up cold and it runs for about 10 minutes and stalls and will not restart.Let it cool back down and it starts again for about 10 minutes. Replaced the OVP relay to no avail. Checked the fuel pressure and all is good.Anybody have any ideas? I was thinking maybe the reference sensor? Any help would be appreciated.

Thanks
Mike

Yes, I've heard the crank position sensor can cause stalling.

MAS relay okay?

Mas
 

Where is that relay located? How about a speed sensor located at the front of the engine?

On the W124? I guess behind the battery, not sure. W126 is behind the firewall, near the ABS brain.

It's got this switch on top I/O, for on/off.

Yeah I was calling the crank sender that, it could be the speed sender for all I know. :D

Hi

Figured out why my 190E 2.6 was stalling( similar cars) and this what i did.

1. Checked the MAS and OVP
2. Checked all fuel system components
3. Fuel pumps and replaced the fuel filtee
4. I connected a home made tester to the diagnostic socket and got the number of blinks which me to the back of the car.
5. Heard air bubbles in the fuel pump area. Checked the gas tank(removed and cleaned, drained gas) and found that the filter inside the tank was all gummed and clogged up. Replaced it and the car ran agian.

I brought to a mechanic speciazling in mercedes to have the lambda adjusted and the car runs like new.

Also, before replacing any part be sure to make sure its not working. Replacing OVP and mas MAY NOT SOLVE YOUR PROBLEM so dont run out and buy expensive parts.

Hope this helps

Stalling
 

I did check the fuel pressure at the distribution block and even when the motor cut out the fuel pressure showed 80PSI. This leads me to believe that it is not a fuel issue. Any more ideas? I did install a new OVP relay,but still the car stalled.

did you do everything that i did to solve my problem?

On a 126, why does the MAS relay have an ON/OFF switch on it?

What's that relay next to it that has a fuse under clear plastic on top of it?

relay next to the mas is the ovp.

mas has on an on/off switch since is its practically a bunch of relays packed together. Essentially the on off switch is the equivalent to pulling a relay.

Crank position sensor is at the flywheel. Wire runs on the driver's side of the engine. I had a stall with difficult restart condition on my 1992 300E when it hasn't been started in a few days. Replaced CPS and worked fine for about a month. Problem happened again one rainy day. Didn't get to solve the problem because the car got rear-ended that same day. Was written off. My next step would have been the OVP. Fuel pressure was fine and the fuel filter was new.

Do a serach for "CPS". Lots of info here. Good luck!

stalling
 

Thanks for the help. I'm actually working on another 300e so I will be able to swap parts back and forth to figure out the problem.I will post my resolution when I figure it out.

Is there a inner tank filter in a 1991 300E? Anybody know?