View Full Version : Troubleshooting Guru's Turns over, won't start when warm on first try

07-13-09, 10:29 PM
I have a 2006 V6 STS with mid 90k's on the clock. I have developed an intermittent problem where, when the car is warm (I make a quick run to the store, taking a trip, getting gas) if I turn the car off, come back a couple mins later, on the first try to start it, it just turns over and won't start. On the second press of the button, it fires and runs fine. So far, it hasn't taken more than 2 tries to start.
This happens about 1 out of every 5 warm starts.
When the car is cold, it has NEVER failed to start on the first try. I have changed the spark plugs and recently the timing chain was replaced by the dealer.
There are no codes.

To me, this sounds like a fuel related issue, however, I don't know where else to go....

Have any techs ever heard of this? Common problem? Ignition or fuel related?

07-14-09, 09:23 AM
I am no technician but it sounds to me like the fuel pump. I had this issue on another car like 10 years ago and if I recall correctly, that fixed it. I think the dealer called it "pressure bleedoff" or something.....

07-14-09, 09:42 AM
If it's the fuel pump, wouldn't it be more prone to happen on a cold start? I was thinking vapor lock or something originally.

07-14-09, 09:48 AM
If it were my old '97, I'd call it a FPR leaking and then flooding the hot engine (the extra gas tolerated when cold).

Does the V6 have a similar possibility?

07-14-09, 09:57 AM
Reading some other forums on Mercedes, they talk alot about the Camshaft position sensors. I kind of had that feeling as well.

Has anyone else had this problem?