a3 8p 2.0 fsi issues badly need help please

[a3tony]

hi all, i don't really know my way round an engine that well apart from the basics so any advice will be great! its a 2004 model and well looked after,regularly serviced and has covered 60,000 miles but im having a few problems, problem 1)basically more often than not it takes 2-3 turns of the key to get it started, problem 2) between 2000-4000 rpm it sounds like its pinking (fuel igniting too early im told) and not feeling as smooth as it should? so i had it put on a diagnostic and it said something about INDUCTION DOORS MALFUNCTION??
Last but not least, has anyone heard of the fuel rail between the head and inlet manifold melting slightly against the head causing it allow air in? mine has done this which in turn was flipping the gasket and allowing air in? the garage i took my car to put some sealer along the top of the fuel rail for me as a temporary measure until i can find more out about this which has stopped the air leakage for now. i rang audi today to ask if it was common but they said it WAS quite common with the 1.6 model but not the 2.0l. if it is common does anyone know of anywhere i can get a cheap one from as with crimbo round the corner im really strapped lol!
SORRY FOR THE ESSAY!
once again any help many thanks!
tony

 

[Khufu]

When you say turns of the key do you mean:

you turn the key, hold it for a few seconds but while the engine turns over it doesn't start so you release & try again? Or does the engine not turn over at all?

A more exact diagnostic code would be handy. 'Induction door' sounds like a translation - manifold flap? You could try pulling the air intake off just before it goes into the throttle body and look at the condition of the flap in case its sooted up. Spraying it with carb cleaner etc can help clean it up & make sure it turns smoothly. Its possible that the mixture is getting weakened resulting in loss of power due to the air leak. Can you see where it was leaking? Picture? I will take a look at mine tomorrow.

I run mine on Super plus petrol but it runs fine on normal unleaded too so that shouldnt cause any pinking.

 

[a3tony]

cheers for the reply bud,
the engine turns over fine but just doesn't start,
ive had the throttle body off and cleaned and that seems fine, the air was leaking between the 2nd and 3rd pots on the top of the fuel rail right up against the head,
ive tried running it on super plus but it doesn't sound or feel any different
i'll get it back on the diagnostic tomorrow and get the full fault code from it,
cheers for your help