Volvo Repair: volvo repair, rpm, volvo

Question
My 1991 740 wagon has been giving me trouble. When I sit it idles between 0 and 500. A friend looked at it and tried to adjust the idle, but it wouldn't go very far, so it did help much. Sometimes the RPM's dip while I'm driving normally- like at about 40 mph. Now, it has been dying. It will the RPM's will dip while I'm driving and it will sputter and die. I know if I go to a shop it won't give them a problem, and I'd like to give a better explanation of what's going on with it. Thanks

Answer
This car has a self diagnostic with memory. Have a repair shop go in and see if there are any trouble codes in the system. This will give them an idea of what may be the problem.
Idle on these cars are set by the computer, the adjustment valve only sets the base idle for the computer to start with.