Volkswagen Repair: Volkswagon starting problems, air fuel mixture, mixture problem

Question
QUESTION: I have a 2001 New Beetle.  1.8 l turbo.  When I go to start it in the morning it will turn over, start and run very briefly and then stop.  It wont stay running. After about the 3 or 4th try it will start and then stay running.  Ive brought it into the dealership twice.  The first time they checked all the grounds and said it was a ground problem, the second time they replaced the o2 sensor.  Things were fine for about a week or two and now its experiencing the same problem.
ANSWER: Sounds like a air fuel mixture problem. Is your check engine light on? Or the immoblizer light on. O2 sensor and ground problem will kick a fault in the engine module. Like cause is a Engine temp sensor reading the wrong temp. A dirty or bad throttle body, or  a vacuum leak. Fuel pump is possible. Preliminary engine management checks are required for correct diagnosis. I will assist you if you need it.

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QUESTION: No trouble light comes on at all.  The cold engine light is on, but thats normal for a cold engine I guess.  

Answer
Still the preliminary checks need to be looked at. Engine temp sensor reading the wrong temp. A dirty or bad throttle body, or  a vacuum leak. Fuel pump is possible. Preliminary engine management checks are required for correct diagnosis. Does your engine stumble when it starts up then die? Or run smooth then die? How long do you have to crank to start? How long does it take to die?