300E Severe Stalling - Undriveable
 

Chalk up another. As I have seen in the archives, a lot of 300e cars have had severe stalling problems. Mine is now off the road because of it. It will start and then immediately stall. I limped home with it having a severe miss, loss of power and stalling. Several times after stalling, though, it would run perfectly. The fuel pump is running so I suspect the electronics or sensors. My airflow sensor was diagnosed as poor a while ago, so it may have failed me.
I will keep this post updated. I am going on vacation soon so I'm going to check wires and vacuum lines but I'm not taking it to a mechanic until August.

Do you get the ABS light coning on when it's running poorly?
Gilly

Unfortunately, the ABS system has been disconnected on my car. I don't miss it except that it doesn't indicate if the OVP is working. I took the OVP apart and couldn't see anything wrong inside. The zener diode looks good, but I didn't test it. I likely will later. I am mostly concerned with how to get the car to the mechanic; both shops I go to are 40+ miles away. I should buy a trailer or tow bar with the number of times I have to move my family's dead cars.

I feel your pain....

Turn on the ignition and pull the fuses on the OVP relay and see if you have battery voltage at the fuse connector. If so.. the OVP is fine.

I would look for vacuum leaks (common) or start checking out the fuel system as per the CD. If the pump or relay were bad, I doubt you would be able to drive it

Tinker

Dont know if this applys,dont know if 86 uses a maf , My 93 300e would not idle and was a pain to start one day out of the blue the car would run and was drivable but had to shift to neutral at stoplights th keep the revs up,

scan code showed MAF mass airflow sensor , replaced it wasnt a cheap part but under $200

dont know if these just go bad like mine did , or deterioate slowly

I've got a 91 300e that is doing the same thing.....
My ABS light did come on when it started to do this.

Thanks
Jared:eek:

If your battery went dead, it's probably your voltage regulator. I was driving down the freeway when mine went bad -- started missing badly, stopped and started a few times, then it was done.

It's attached to the underside of your alternator and two phillips screws hold it in. Pull it out and see how long the "brushes" (two contact poles - spring loaded) are. If they are grooved and worn down, then that may very well be your problem.

Good luck!

~Paul

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'91 300E, 215K miles

Thanks,

I'll check it out

-Jared;)
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91 300e, 94K Miles

Checking the voltage at the OVP fuse doesn't tell if the relay is good or bad, the fuse is on the live side.

Paul -

I changed the voltage regulator, the problem stopped for awhile (2days) and now it's back. I checked the OVP ant the 10amp fuse was blown. I replaced the fuse, still no change. Should I replace the OVP, or am I barking up the wrong tree?:confused:

Thanks,
-Jared

WOOF!
 

You're definitely barking up the right tree. If your OVP fuse wasn't blown before (or even if it was) and it's the original that has only one ten amp fuse (see pic) then this is the likely culprit. ABS light is a giveaway too. Change it out and see what happens. If anything, you will have to replace this part sometime during your car's life, either now or later. Part # for the bad batch of OVP's is 201 540 38 45.

http://www.members.aol.com/vandrysen/OVP.jpg

Good luck!

~Paul

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'91 300E, 215K miles

I just got back from a 3 week vacation. My car healed itself! I think that it had a wet connection which dried while I was away. I am going to examine and clean all connections that I can find. If I find anything obvious, I will update this thread again.

Gotta love cars that fix themselves :)

Your comment about getting wet made wonder if the cover is in place behind the battery. It is the one the covers all the electrics directly behind the battery.

My MAF gave me problems regarding the AC ... I noticed that alrhough the cover was in place, the top wasn't quite completely in allowing rain, water etc to get in. The bottom of the MAF was slightly corrorded.

Just a thought.