good spark but not firing?

[steve wilton AM]

hi all, ive s3 thats been sat up for few months tried to start it but there was no firing at all, i think electrics are all ok as ive tried every plug and theres a good spark from all.i sprayed a small bit of easy start onto air filters and it fires up and runs ok but even running for 5 mins when its switched off it will not start or fire ,spray a bit of easy start again and away it goes.i think its petrol related but where would you start? any ideas welcome

[Barkychoc]

You really need to work your way through the injection system. Can you hear the fuel pump humming / buzzing for a few seconds when you turn the ignition on? (Its under passenger side rear wheelarch on V6 I think).

[steve wilton AM]

yes can hear the pump on as the key is turned,would i be able to check for fuel at the injectors the same way as you can with a diesel?

[phillpot]

No but there is a valve(like a tyre valve) on the fuel rail (some are alloy some are pressed steel) sandwiched between the inlet manifold and plenum. Should be fuel pressure behind it when ignition is on, plenty of rag around it before you depress it!

Edited by phillpot on Monday 30th July 16:52

[steve wilton AM]

hi,tried the valve and there's loads of petrol coming out when the ignitions on,any other thoughts,ta

[Julesprivate]

steve wilton AM said:

yes can hear the pump on as the key is turned,would i be able to check for fuel at the injectors the same way as you can with a diesel?

http://www.youtube.com/watch?v=XabbJ3HaeuI&feature=related

Not that I recommend you try it...

[Barkychoc]

So once it fires up with easy start does it continue running I'm not quite sure what you are saying.

Has anyone mentioned the yellow connector in the steering column that burns out?

[steve wilton AM]

when i spray a small bit of easy start it fires up and runs fine,have left it ticking over for 20-30 mins,sometimes the revs idle and it sounds like it might stop but if you blip the throttle its fine again,but if i switch it off even after 15mins running it will not start !no one has mentioned any thing yellow!,ta

[phillpot]

That's wierd


Long shot but is there a (strong) spark when you crank it?

Easy start could be self igniting (bit like a diesel) then, somehow, ignition coil gets a feed once you release key from start position?

If you crank for a while then take a plug or two out are they wet?

Have you got the room and energy to try "bump starting" it ?

[Barkychoc]

Take + wire off the coil and wire it directly to the battery and see if the fatherless thing will start.