slobodan

Ok, I have a 99 clk 320 with 104k on it. over the last week or so I start the car up from a cold start and it runs fine for like 3-5 minutes and when I come to a stop it dies. Then it takes a few minutes of cranking to get it to start. Then the car runs fine for the remainder of the trip. It acts like it its not getting any fuel and the starts and runs fine. This happens before the engine is up to normal temp and the car runs normal until then. There are no codes or check engine lights. Everything appears normal until that happens. I was thing maybe a relay or failing fuel pump but i'm not sure as it happens when it's just warming up. Any Ideas would be greatly appreciated before I order a pump filter and relay..Again no codes

Serndipity

sloboday.......MB did not fully implement OBDII on our W208s (e.g. our OBDII connector only provides a single ended K line signal as well as a MB proprietary protocol), which was just enough for state emissions testing.

As a result, most OBDII scan tools will not provide the required DTCs (e.g. diagnostic trouble codes), which would be otherwise available, using the 38 pin diagnostic connector, located in the engine bay and the MB STAR diagnostic software.

At this time, I would add to your list of suspects, the 'crank shaft position' (CPS) sensor, especially since that has been an ubiquitous maintenance issue on both the W208 (M112 and M113) engines and you indicated that the 'no start' occurs after engine warm up.

Specially, if the engine control module (ECM) does not get the correct signaling from the CPS, it will cut off both the fuel supply and spark.

IMHO, you have a $100 or less DIY issue.....if you guess right.

EdKramer

That's the problem with most DIY'ers on here, just guess away without applying a structured, symptom based approach to diagnostics. Much the same as the main dealer "factory trained technicians"... Yep, trained to just take a wild stab in the dark at the most likely candidate (ie, most expensive, usually a control module of some sort) and just replace it, only to have the customer return the following day, week, whatever, with the same fault. Oh sorry sir, we can't return the $1200 module now that's it's been fitted, even though it didn't solve your problem...

In this case, you might be lucky and guess right and get away with just a $100 part, or it could be something else.

As for W208's not having full OBD2, not sure about the US market cars but here in the UK my '99 CLK has full diagnostic capability with STAR, although my crappy iCarsoft thing, even with the proper iCarsoft 38 pin to OBD2 adaptor, I can still only get engine codes, so need to visit my Indy for a more thorough investigation. But, at only £30 for a full scan, it's money well spent for the clues it gives in my diagnostic process. Compare that to over £200 for a scan at the dealer...