Hi Again Drew,

You asked about online service info. I'm having trouble finding
the text file I have somewhere for links. Maybe because I'm on pain meds from carpal tunnel surgury yesterday. :-(
Here's one clue from the brick search engine:
http://www.autoelectric.ru/auto/volvo/960/1993/960-93.htm http://www.autoelectric.ru/auto/volvo/940/1993/940-93.htm http://www.autoelectric.ru/auto/volvo/740/1989/740-89.htm

I think there's more stuff there but I can't locate the index with it's
stubborn server, and a previous index noted on the brick files is dead.

There's another good collection to be found if you search "https" on the brick
search engine.

Still there's no substitute for the volvo wiring greenbook for your car.

You might just get some CRC air mass meter cleaner and try that before giving up.
You need to make sure that there's no air leaks in the air ducts between the AMM
and the throttle body.

You should attend to pesky vacuum leaks common with old rubber tubing.
Replacing all of the vacuum lines every 20 years doesn't sound unreasonable :-)

Bill near Boston