reynoldss

I have an Audi A4 Quattro 2003. Pretty neat car. But here's what's happening: When I turn the key, I hear pressure forming from the fuel pump. But there is no start. I could turn the key 50 times and it still won't start even though I feel like there is more and more pressure. I thought it might be a fuel pump or a fuel filter issue but I'm not getting any codes on those. The only way the car will start is if it is jump started or hasn't been sitting for too long. Also, all the lights turn on on the dash, headlights radio works and all. So it doesn't seem like a dead battery. However as I've said, the only way for it to start is if it is jump started. This is really confusing.

Steamboat

What codes are you getting?

Does the car turn over when you turn the key?

Have you measured the voltage at the battery?

reynoldss

The only code I'm getting is a P0421 code which I had gotten checked out and told I shouldn't worry about for another 6 to 8 months. The check engine light is off however.
The car does not crank or turn over when I turn the key.
The battery mesures at 12.8 V.

Steamboat

My guess would be that you've got a weak battery and/or your battery isn't getting charged properly. I can't think of another cause that would be solved by jump starting.