Dan --

In the US, '82 Volvos came in two flavors: The first using the early LH-jetronic (electronic FI, with an AMM), and the last of the (non-turbo) mechanical FI, the K-jet systems (which I have), using a fuel distributor.

The '82s with electronic LH-jet were probably more West Coast cars (for emissions reasons).

Did you really get a new AMM (LH-jet), or did they replace the fuel distributor (K-jet)? Sometimes a mechanic will call the fuel distributor an "air mass meter". However, those mechanical gizmos are subject to gumming up -- the air baffle can get sticky at idle position (particularly if not lined up properly) and cause stumbling and stalling at idle, particularly if there are a few small air leaks.

Both FI systems suffer idle problems with a worn out CIS motor (constant idle speed). The CIS motor is mounted under the intake manifold on an LH system, and over the manifold (near the valve cover) on a K-jet system.

When my CIS motors have failed (on an '81, an '82, an '83, and an '86), the symptoms sound like yours. Sometimes they get gummed-up inside the valve portion and can be washed out with carb cleaner. But more often, they're simply worn out -- the brushes and commutator in the motor portion have burned too much to be restored.

A good used CIS motor is chancy, unless you know its history. A new one costs around $125.

One other thing -- be sure the throttle switch is working and adjusted so it goes "click" when the throttle returns to idle position.