Volvo: loathing idle, sudden poor gas mileage, mass air flow meter, air fuel mixture

Question
I purchased a 1983 volvo wagon 4 months ago for a super cheap price of $800. ran great except for a starting problem when it seemed to be driven for a while. 3 starters later, which wasn't the problem, as I by passed the ignition switch it mow starts fine. The problem now is that it is ideling irratically and running so rich it almost gags me to drive it not to mention you can literally watch the fuel gage go down as you drive. I have the connector to the mass air flow meter disconnected because the engine just dies If I connect it now. The car got 25 miles to the gallon and ran SWEET except for the starter problem until now. I suspect more wiring problems because as I heard they are "biodegradable" for this model and year. where do I look for the problem? The wagon has 200,000 miles on it. by the way it is the fuel injected b230f model. I'd be greatful for any help you can provide.

Answer
It sounds like you have a classic case of a bad mass airflow sensor.  The fact that you can unplug it and the car runs indicates that.  When the AMM is unplugged, it puts the car into a default air/fuel mixture mode, which is designed to keep the engine running in a very rudementary fashion, with the side affect of horrible fuel economy and bad performance.  When you plug it in and the car dies, means the AMM isn't sending a proper signal to your emissions control computer, and in turn, the computer doesn't have the right information to give the engine a good mixture ratio, usually meaning the engine will run lean and stall out almost immediately.  Good luck!