1988 Mercedes 300 E 2 yrs car stalling
 

For almost 2 years now my Mercedes has been having a problem stalling. 1st my ABS light on then off intermittingly and now the ABS light on all the time. 1 1/2 yrs ago the car started this problem & finally figured out if I tapped this little black box under the hood on the front left then it would start, after stalling at a light or behind a car. Now it stalls when I am driving down the road with no warning, at 1st when it was going to stall it would seem like it was losing power, now it just dies. Anyone have an idea of what is happening? I really don't have the $$ to go to the dealer MB, so I have been driving on a prayer lately. Has this happened to anyone before?
Thanks (please help)

Mine is not a 300E, but had same symptoms for over a year. But I know your car has this part too.

After swapping many ignition related parts still did not resolve my problem (I didn't cared :rolleyes:, bc I looked it as preventative maintenance & I was keeping my car anyways).

One day I was in for parts once again & decided to ask my MB service advisor to see if he can tell me what the problem might be. Without hesitation, he said "fuel pump relay". I thanked him, but I though how can it be...it's electrical...so either it works or it fails, can't be intermittent.

I mentioned it to the guys at parts, they suggested why not...you replaced everything else already. :D

SO I DID, it solved my problem!

To this day, I can duplicate my stalling problem once I install my old "intermittent" fuel pump relay back on. :eek:

Replace the OVP and problem solved.
Do a search, endless threads on it.

It'll probably be one of those two. I had the problem and reseated my fuel pump relays and it stopped. My daughter needed a new OVP relay and new fuel pump relays but not sure which one fixed it as I just did both.

The ABS light points to the OVP relay.

Don't think a bad OVP relay will stall the car? Will it not just put it into "limp home mode"? But I could be wrong....

But a bad/intermittent fuel pump relay will stall the car for sure.

It will cause stalling. ABS light and stalling = OVP 99 times out of a 100.

That's from personal experience or from threads you have read?

I am tempted to pull the OVP from my car & drive around without it to see if my car stalls. I am curious, BUT not that curious as to risk damaging the computer, etc. with possible voltage surge.

My car is 27yrs old & still have the original OVP!

My 89 300E likes to do the stalling every few months, like twice a year. I drop in a small can of gasoline "dryer", I think any brand will do, and the problem immediately is gone. I think mine and possibly other 300E's are very prone to suffer from small amounts of water in the fuel.

When the OVP fails to power up the ABS light will come on. The ABS turns the light on when the power supply is less than 9 volts hence the light when the relay fails. Stalling isn't a certainty when that happens. When the engine module goes off line the engine can run on the baseline settings without ECU intervention. Stalling occurs if the computer has adjusted the running parameters enough that the transition back to baseline settings is too abrupt.

Its how I got my 300TE for a cheap price ;) PO's and their "mechanic" couldn't figure out the stalling and ABS light. Walked in their, bought car, got home, put new OVP in, solved :)

Thanks for the explanation.

The reason I was hesitant to belief a bad OVP will cause stalling was bc MTI has a few posts that states a bad OVP will cause the engine to run very rich & defaults to limp home mode, engine will run bad/no power...but will get you home.

It will, but it also causes stalling. A search will reveal thread upon thread about this. Every person's OVP fails, period. Whether you get stalling is a 50:50 shot. ABS light will come on every time though.

Thanks, I agreed with that.

I also read that a bad alternator will cause the ABS lights to come on & stalling as well. But I don't think this is the case with the OP, 2yrs...his alternator/battery would've died already. :D

Don't you hate it, when the OP doesn't come back to finish off his thread!

bad alternator will kick on all the dash lights -- basically its telling you impending doom and you will soon be stranded once the battery is out of juice.