This is my kid's car. Here's the entire serious of checks and the symptoms. I haven't worked on the car at all until recently; I got all my info from Kev, my son.

The first thing I told him to check was the fuel filter. He did, and it was partially clogged. he replaced it.

He then told me no fuel was coming out of the tank. I told him to look at the repair cd's to make sure he was looking at the correct line. He's too smart to do that, so he pulls the tank. It was clean, the screen was clean, he was checking at the fuel filter outlet. The line coming from the tank flows fuel freely.

I am sure this is not a fuel problem.

He had the car at a buddy's shop. They put a real battery load tester on the battery and it failed miserably. Replace battery. Thats seemed to help. He went to pick up the car and a block away from the shop, the car dies again.

They test the alternator. It is marginal. They replace the marginal alternator. Seems fine, until he drives away.

So now I get involved and visit the place he has the car.

here's how it goes:

Cold start, fires right up, idles fine, and at around 50c coolant temperature or so, the idle jumps up to about 2200 rpm or so. It runs like this for anywhere from 15-45 seconds, then abruptly shuts off. It doesn't spool down slowly; it shuts off.

If restarted immediately, it jumps up in rpm almost bright away, and dies after about 15 seconds.

While in this process of dying, I sprayed started fluid into the air valve. The engine did not pick up at all in RPMs and died. So, something electrical.

What could cause the engine to shut down electrically AND cause the rpms to jump up for 15-45 seconds? Does anybody here have the suspect controller we could borrow and try out, and then buy if needed?

If after the first event, the car is allowed to cool down, it takes longer for the process to occur. So, somehow, this is related to coolant temperatureas well.

He had a known good OVP and tried it. Nope.

What do you think the issue could be? I am not around to help him, but I'd like to save him some money. He's going to tow it to a Euro-car repair place. I can just see the $$ racking up and he doesn't save money like kids should.

 

Hi waybomb,

I have the same car with very strange electrical problems. Occasionally (usually when the car is warm), it will start acting like the battery is dying: lights, radio, wipers, etc all get weak or stop working entirely. Then, something happens and the engine revs (I can only guess from the sound b/c the tach has stopped working too) and voila! everything starts working again. It is not the alternator or battery; there is a problem with a grounding cable or something else (in the dashboard perhaps). Unlike yours, my engine hasn't died (yet). This problem is going to be tough because it is intermittent!

Good luck, and let us know what you find.

 

You have a long history and familiarity with the Mercedes product. So, I don't want to suggest anything insulting to that intelligence. However, in your description of the symptoms you've cited, did you consider spark/timing issues? Could it be, that the timing chain may need to be replaced? As stated, I don't want to insult your intelligence, as I know little to nothing about the model itself.

 

Not a timing issue.

Latest update -
Spraying starting fluid into the intake flapper keeps the car running when it wants to die.

Jumping out the fuel pump relay keeps the engine running after it has died.
swapped out fpr with a "known" good one, and it still dies
swapped out ovp with a known good one - no change

Only happens after 50c; closed loop

so, either the "known" good used fpr is bad, or something is switching the fpr to an off mode.
Or something completely different.

Any ideas?


ps - don't worry, I am thick skinned - I'd love to look like a fool on this one just so he could get the car running and out of my 202!