Intake leak

[njspider]

I'm chasing an intake leak on my FI 1982 spider. What is the function of the aux. air regulator?

[seawood]

Perhaps not the smartest way of finding that leak, but being a guy, I have an excuse..

Get the car running, and with a can of starter fluid try a very short squirt at the shaft on the throttle valve , rpms increase, you have unmetered air getting in. Shaft is worn. , perhaps the rubber intake hose has a crack, connections are not tight.

Aux air reg I think has something to do with starting the car when hot or cold. There is a piece of bimetal material in there that contracts or expands with heat/cold. Anyway, been 10 years since I had to deal with mine, memory is slipping now.

Used to put the thing in the freezer for a while and that bimetal piece should open right up.
Here is a post from a number of years ago: https://fiatspider.com/f15/viewtopic.php?t=25316

[davidbruce]

The aux. air regulators job is to introduce more air to the engine when cold. Raising the RPM's. And then as the engine warms up the AAR closes. Basically an automatic choke for fuel injection. Some good info in these posts:

http://fiatspider.com/f15/viewtopic.php?f=5&t=22898

http://fiatspider.com/f15/viewtopic.php ... ss#p301270

https://hpsimotorsports.com/blogs/tech- ... -1982-1989

If you still have the original air intake hose. I would inspect it very carefully.

[njspider]

Found it. Tested the vacuum advance on the dizzy with a vacuum pump. Not moving the plate in the dizzy and not holding a vacuum. So no vacuum advance on the ignition timing AND an intake leak. Replaced the advance mechanism and now the car runs better than ever. Low end torque is back and it revs smoothly.