Revs dropping and cutting out

[Ian_83]

The battery ran flat the other day (my fault). Ever since the revs bounce about when returning to idle. For example, if driving along, i'll dip the clutch, the revs will drop to 500 or so then bounce back up to like 1100 then down again and settle. I'm thinking the battery may be damaged off the discharge, since it was completely flat not even the interior light would come on. Otherwise, idle control valve maybe? Its an AGU so its on a cable throttle.

 

[A3 Oly]

mmmm exactly the same issue here matey. noticed this the other day, it also cut out on me when taking it out of gear at the lights.

 

[A3 Oly]

could this be a broken tip?

 

[murran]

i bet the throttle body is really dirty. having the flat battery has wiped the throttle body adaption. because its really dirty, the ecu cant work it out.....
you need to clean the throttle body and carry out the basic setting on vag-com or other diagnostic equipment

 

[chapmanvr6]

Sounds a similar kinda thing to what mine was doin when the alternator went, may be summit different but just a suggestion.

 

[Welly]

Sounds like a vac leak to me...

 

[leighlo]

Exactly the same problem here - the alternator was replaced on my car last week. I'll book mine in to check this out and let you guys know if I get any updates.

 

[steve bain]

i bet the throttle body is really dirty. having the flat battery has wiped the throttle body adaption. because its really dirty, the ecu cant work it out.....
you need to clean the throttle body and carry out the basic setting on vag-com or other diagnostic equipment​

second this....common fault apparently after dead battery
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