stingerbtle

I have a 98 A6 2.8 Quattro. It starts every time when it has been sitting or it is cold outside.
However, after i drive it and it warms up and turn the engine off, it won't start back up until it gets cold again. New batterie and everything has power. It will not crank at all.

Harleyguy

Check the main intake plumbing for a cracked or damaged tube. This is a common problem. When cold the tube contracts enough to seal the crack tight enough to allow the MAF to have the correct mixture for start-up. When it is warmed up the crack opens up and the MAF doesn't read the air flow correctly and you get the wrong air:fuel mixture for start-up. These often crack on the underside where it is next to impossible to see and require different detection methods. If you haven't already, you can run a scan that will give you better information.

johnkk

Crank position sensor often causes this symptom. Search the forum on CPS.

meternerd

Coolant Temperature Sensor.....it "thinks" the engine is cold and floods it with fuel, even when it's warm. At least that was the exact symptom on my 2.7T. There is more than one type, so be sure to order the correct one.