Additional Air Slide Valve

[Guest DazH]

Hey guys,

Today I performed open engine surgery on the E28 again to get to my 'Addition Air Slide Valve' Which looked something like this:

Its job is to provide additional air to the engine when it is cold to increase the revs, Therefore getting it hotter, quicker. Kinda like a choke would with fuel I guess. I suspect mine has failed/defective even though my obviously very talented mechanic tested it as fine. My findings go against my mechanics results.

*My Problem* The Engine Revs its nuts off until it gets warm and settles down to normal idle. It takes about 10 minutes of driving to get the temp up and in that time, the car is revving at around 2000RPM. This is going to ruin my newly built engine pretty quickly

This is a picture of MY valve at normal room/street temperature:

and when hot (in boiling water):

-

I found this site that shows someone testing their valve and the results differ from mine quite substantially

Room Temp:

Hot:

-

What do you guys think? Change it? Its quite expensive but I need to do something...

Cheers,

Daz

[Guest Mister Dabsy]

Not sure on this one fella... BUT, it obviously works like a normal thermostat, in principal, so how about soaking it in something that will clean the spring to free it off? Could use anything really, as long as it gets a good rinse afterwards ! Gotta be worth a try matey ;)