73 VolvoES. High idle when cold only.

Hello, I have a friend with this car and after fixing some Djet wiring (not sure what was involved) and installing a reman AAV (don’t know where he got it) when cold starting his engine races @ 2400 RPM for about 60-90 seconds, then settles down to normal idle @ 900 RPM. Timing has been checked and reset. AAV is working normally (visually inspected piston/slide when cold and warm and it fully closes). New air filter was installed over the winter.  He checked for air leaks around the AAV hoses and at manifold and made sure connections were tight. Car is running very well except for the high revving at cold start up. 

I’ll be asking him what he did to the wiring and where he got the AAV.  

What would be things to check further? 

thanks, 

Craig. 

Hi Craig,

as rpm comes from air and can only de pushed down by fuel, you have to search for air leaks. AAV is first suspicuous part.