190e 2.6 cold start issue
 

My car has developed a starting problem lately. When the car has been sitting for a while (engine cold), it cranks and starts up, but then stalls right away. It feels like a fuel shortage. When I crank it a second time, it starts and runs fine. This behavior is very consistent, happens every time. When the car is warm, there are no problems.

Below are some videos that show the problem (MPEG4 format, plays fine in QuickTime). If anyone has suggestions about what may be wrong, please comment.

1. A cold start:
http://foonetwork.com/media/benz/190coldstart.mp4


2. A warm start:
http://foonetwork.com/media/benz/190warmstart.mp4

I had a similar problem. I put some of that fuel injector cleaner in with a tank full of premmium gas and the rough starting stopped. I am pretty sure that is not the root cause but it helped me immensely.

Thanks for the suggestion. I forgot to mention that the car was purchased recently after sitting for over a year. It was very sluggish so I used some injector cleaner, as well as a can of BG44k and also cleaned the intake/throttle body with another BG product. The car started running much better but then this problem appeared.

Someone told me about a valve that prevents fuel from leaking down towards the gas tank when the car is not running. If the valve goes bad, this exact problem would happen because the fuel pump needs a few seconds to pump fuel all the way to the injection system. However, I am not sure if my car even has such a system in place. Any ideas?

The engine is 103.942.

Could be a sticking or bad Cold Start Valve. Also could be a bad Water Temp Sensor, tells the CIS-E computer to fire the cold start valve. Or bad OVP Relay. Does it high idle once started on the second try?

It does have one but that normally affects warm restarting, such as when the car has been sitting for less than 30-45 minutes. Once you turn the key to the on position the fuel pump, or pumps, prime.

Once started on the second try, it idles at around 900-1000 rpm for a few seconds, then quickly drops to its normal 750 idle. Shouldn't it have a higher idle for longer periods of time when it's cold? My other cars ('05 C230, '00 Audi A8) are idling at 1200-1300 rpm when cold, and they don't drop their idle as fast as the 190E does.

When cold out, ours high idles for 8 - 10 seconds on cold start. In warmer weather, typically 2-4 seconds. Our other cars have idled higher longer to maintain emissions low, but the MB just stays high just long enough to make sure combustion can be sustained.

Steve