Won't start up!

[A31.8T]

Hi, so I'm having a bit of trouble of getting my at to actually start up.
Wa driving normally, and having switched off the engine, I was unable to re-ignite the engine. Letting the car rest for 20-30mins and gave it another try and it worked. I then kept the engine running, and the problem occured again. I was again unable to start up my engine after switching it off.

I doubt it's a dead battery since if it was, it wouldn't be totally flat. I.e I would have had signs of the battery dying. Longe starts ups etc. Any ideas?

Thanks in advance

 

[Broken Byzan]

What car is it? Engine?

 

[S3KO4]

sounds like the immobilizer is at fault!

 

[A31.8T]

A3 1.8t not quattro. Sorry about spelling mistakes on phone. Definately not battery since radio works.

 

[AudiiduA]

Sound like a MAF fault to me, Get it checked on VAGCOM! when your engine is HOT the air/fuel mixture needs to be leaner! if ECU thinks its a cold engine its richens mixture up, like choke on older cars! then it will struggle to fire untill engine has cooled like you say! maybe air temp sensor too as a thought??

 

[A31.8T]

Hmm no idea. I'm clueless, just stuck in car trying to boot it up wert now and again.

 

[AudiiduA]

Hmm no idea. I'm clueless, just stuck in car trying to boot it up wert now and again.

If its turning over fine its not battery! unplug MAF and try it! just a thought! deffo sounds like a fueling issue!

 

[Keeno]

MAF. Used to get a similar thing - start it up, splutters and dies. Fire up the second time, no problems.

 

[Broken Byzan]

If dropping the MAF off makes no odds, and the immo light isn't flashing.

My best guess without any fault codes would be the crank sensor, quite common to be intermittently failing

 

[A31.8T]

Guys thanks for the help! Having worked through the advice, it turns out to be the immobiliser. =D but another quick question, having jumped started the vehicle, after switching the engine off. It don't turn back on? Could it be a problem with the alternator?

 

[finesse]

I'm having the same issue, randomly.


Steps am taking this weekend, I'd suggest you also try;

Cleaning throttle body
Cleaning MAF
Changing temp sender

If dropping the MAF off makes no odds, and the immo light isn't flashing.

My best guess without any fault codes would be the crank sensor, quite common to be intermittently failing

1. "Sorting" the crank sensor, is that a big job
2. Using a temp sender from GSF parts, would you recommend?

 

[voorhees]

1. "Sorting" the crank sensor, is that a big job
2. Using a temp sender from GSF parts, would you recommend?

I went to Audi for my temp sensor but I have never heard of any problems from GSF ones.....never knew they did them but if you were to ask about coilpacks that would be a no no on the cheap ones.

 

[finesse]

I went to Audi for my temp sensor but I have never heard of any problems from GSF ones.....never knew they did them but if you were to ask about coilpacks that would be a no no on the cheap ones.

GSF sell the green sensor,

GSF = £16
Audi =£31