Originally Posted by sonoronos
Check the mercedes boards if you don't believe me.
Here's an easy test:
1. Use AC Multitester
2. Disconnect CPS
3. measure AC voltage across cps while cranking.
4. if you have voltage, then the CPS is fine. If you don't have voltage, then your CPS is broken.
Have you noticed that the problem is getting worse over time?
The problem hasn't really become worse over time - it is really inconsistent, but if I had to show someone I would drive the car hard and then let it sit for 30mins, then go and crank it.
Can the CPS be intermittently 'broken'? In other words, if I remove it and measure voltage while cranking, will it read good sometimes and bad the other?
I did check the MB boards - and most of them seem to think it is a fuel issue.
For the record, the car has never stalled, or tried to stall at a stoplight like a lot of the CPS problems I read about. It did have one episode where my wife let it idle for 15mins in the AM while she finished getting ready for work. She went out to the car and the car was running rough with a check engine light. She tried to pull it out of the garage and it was running so bad she pulled it back in and took another car. I got home to check it out and all was well.
SQ