Fast tick-over

Hi,
Mk1 Gti 1.6 engine prefix EG
Engine number suggests manufactured in 1979

Problem with fast tick-over - 2,500 rpm.

Engine does slow down when the air from the auxiliary air valve is
restricted but nowhere near slow enough.

I think that the problem may be with the 'plumbing'.

There appeared to be a Heath Robinson modification made to the
air supply which I have removed.

I have attached two photographs.

Photograph 1 shows the cut off rubber connection from the auxiliary air
valve to the manifold and the single connection to the manifold.

Am I correct in thinking that these two should connect?

Photograph 2 shows another connection to the manifold that was connected to
the connections in photograph 1 by a home made 'T' piece.

If the two positions in photograph one are connected where does the one
in photograph 2 go?

Any assistance very much appreciated.

 

Your aux air valve may not be closing. Is it only when warm it idles fast ,or also when cold?

 

Hi,

Thank you for that
It runs fast when hot or cold.
If I restrict the pipe from the aux air valve it does slow down quite a bit

Cheers

 

That does suggest that the ISV isn't closing

 

Many thanks for your help.
Have a spare valve so will fit and try again

Cheers