I have a 2001 A6 Quattro. It is having intermittent starting problems. It has happened 3 times now. It runs great, but every few days it seems like and when it is 90+ outside it will crank over, but won't start. The first time it happened to me the car had been sitting all day at work. I tried to start it, it cranked, wasn't starting and eventually the battery started dragging. i let it set for a few minutes tried it again and it started right up. The same day, a couple of hours later it did it again. My son had it this time and he tried to jump start it, didn't help. Finally he sprayed starting fluid in the throttle body and it started. Runs fine after it starts, no cutting out or sputtering. We replaced the battery, which wasn't holding a charge, and was fine for about a week. Today it happened again. Drove it to the mall, all was fine. After shopping for about an hour (again hot outside) came out, it wouldn't start. Cranked over, but that's it. When the key is in the on position the fuel pump was not turning on. When cranking the car it wouldn't turn on. After about 20 minutes i was cranking it again and after about 30 seconds I held the gas pedal to the floor and it started up. Ran fine after that and has started four or five times after that. Any ideas???

 

So today the car started as normal, was running fine...i stopped at the bank and when i started it to leave it was missing/shaking. i shut it off and turned it back on and same thing. i drove it back to work, runs decent when moving, sluggish on the takeoff and has a really rough idle. After I got off work I took it to the dealership and they scanned it. here's what it came up with:

My fuel ratios are all good. The event memory listed these codes:

P1479 or 17887 (not sure which one the code is)
Brake vacuum system mechanical malfunction-intermittent

P1602 or 18010
Power supply terminal 30 voltage too low-intermittent

P0300 or 16684
Random/multiple cylinder misfire detected-static

P0301 or 16685
Cyl 1 misfire detected-static

P0303 or 16687
Cyl 3 misfire detected-static

P0302 or 16686
Cyl 2 misfire detected-static

P1340 or 17748
Camshaft position sensor-G40, Engine speed sensor-G28 incorrect allocation-static

P1519 or 17927
Bank 1 camshaft adjustment malfunction-intermittent

P0420 or 16804
Catalyst system, bank 1 efficiency below threshold-intermittent

P0150 or 16534
O2 sensor circ, bank 2, sensor 1 malfunction-intermittent

P0130 or 16514
O2 sensor circ, bank 1, sensor 1 malfunction-intermittent

P0322 or 16706
Ign/Distributor Eng Speed Inp Circ No signal-intermittent

We are going to replace the cam shaft position sensor tomorrow, will let you know if that solved the problem.

 

We have replaced the cam shaft position sensor and the crank shaft position sensor and now it also has new spark plugs. Runs fantastic, just doesn't idle worth a crap. : / The dealership says they think that it is out of time. They charge $300 just to test it to see if it is out of time, but if it is out of time it will all be no charge because they did the timing belt. Going to put new vacuum lines on it tonight and see if that helps first.

 

The problem ended up being the cam timing variator

 

After they got it back together it still ran bad. When the variator broke pieces of it went into the motor and bent three valves...