I jacked up My wife's 2000 A6 2.8 to see if I could find where a noise was coming from, which turned out to the cv joint, I was going to change the oil and when I went to start it, it cranks over but won't start. It has spark, and I did a volume test on the fuel pump, the manual says it should be getting 375ml in 15 seconds, I got right at 350ml. Would that be enough for it not to start?
Any suggestions?
I should add since it wouldn't start, i changed the spark plugs, put in new valve cover gaskets and cam seals, put in a new axle. I know none of these things has anything to do with the original problem with it not starting, but it had to be done, I'm now back to the original problem, I still can't get it to start, any help would be greatly appreciated!

 

Hiya

Gonna throw out a bunch of ideas for you

1) What is the battery status, how old? 12v with car not running? Test with Multimeter, should be 14 when running
2) Alternator, last replaced?
3) Check the interior fuse panel, any blown fuses?
4)Fuel flow you mentioned is enough to start, not stop the ignition sequence
5) Coil pack, how old?, did you hook everything back up properly?
6) Vag com codes, do you have any?

 

Thank you for the ideas, the battery is charged, but it does drain. While the car has been sitting, I've had to charge it twice, I had to charge it yesterday to do the fuel volume test. I did check the fuses at the beggining of this debacle, I'll check them again.
To your question "did I hook everything back up properly?" I hadn't done anything to it yet when this first started. All I did was jack it up to check out what was making the grinding noise, and when I foung the axle shot, I figured while I had it up I would change the oil. When I went to start it to warm it up, it wouldn't start.
The coil pack is the original.
There are no DTC's at all.

 

you mentioned that you put in a new valve cover gaskets etc, I would suggest checking all the things you disconected to do the job.

But the fact that your batter had to be charged twice while sitting leads me to two thoughts

1) you have a parasitic drain somewhere
2) The batter is shot and dies fast and doesn't have the cranking power to get the car running quick enough

I'd say try a new battery. Get a good interstate or optima (sp?) batter.

Let us know

 

Thank you, yes I did do all that work, but it wouldn't start before i did all the work. I just went out and checked the battery, and it still has a full charge

 

full charge vs cranking capacity are two different things

 

I can't think of anything related to simply jacking the car up and/or changing oil that would cause a no start. Suppose it is possible it's just a coincidence.
You say it has spark and with 350ml fuel volume in 15 seconds we can ASSUME the fuel pressure is probably OK as well. You have spark so the crank sensor has to be OK.
Try spraying carb or brake cleaner into the throttle body and see if it runs. If it does, you need to check for injector pulse. Can be done with a simple test light. One wire should have battery voltage with the key on. If it does, connect the test light to the other terminal and battery positive. Then crank the engine. The test light should flash indicating the ECM is grounding the injector. It might be hard to see as it'll flash fast because the injector is only grounded for a few milliseconds each time it "fires".
Hopefully one of those checks will find the cause or at least narrow it down.

Thought of one long shot. Unplug the ECT sensor (right rear of engine) and see if it starts then. It'll run very rich at the -40 degree default but it will at least fire up (if the sensor is actually bad) I have seen them fail but not go out of range so they won't set a code. If it "thinks" the coolant temp is 200 degrees, it'll never start cold. Better yet, if you have a scanner just see what the ECT sensor reading is and if it's about what it should be for the ambient temp.

 

I'm wondering if the anti theft would have naything to do with this. I just went out to try locking and unlocking the doors, but the key fob isn't working. I'm going to put new batteries in and try it agin, after i figure out how to re-synch it.
Well, the key fob works now, and it still won"t start, so that wasn't it

 

Ok, I replaced the ECT sensor, sprayed starter fluid into the throttle body, neither worked. I'm baffled!

 

Not trying to flog a dead horse here, but I am going back to your comment about having to charge the battery twice while it was sitting, that clearly shows threethings

- parasitic drain
or
- battery with insufficient amps to crank
or
- bad alternator


Do you have access to another vehicle you could hook to its battery while running and jump your wifes audi to start? That usually will work if her battery isn't too far gone.