Volvo: Volvo dying and surging, mass air flow meter, mass air flow

Question
My son's '93 940 Volvo GLE dies all the time even at high speeds.  We changed the fuel filter from  recommendation on experts.about.com and this seemed to help for a while.  Now it has taken to dying again after a month and in idle mode the moter surges from idle speed to a little faster, back and forth and continues while the car is running.  Any suggestions?  Diagnostic tests ahow nothing!!

Answer
Jeff,
Test the fuel pressure when it dies and see if the pump stops running and that is what is causing the car to stall. Also make sure the feed pump is working and the strainer on it is clean. I am assuming that you have a Bosch LH fuel system. Fuel pump relays have a high failure rate. If the pump system is good test power stage, Mass air flow meter, suppression relay. Those parts are not easy to test so trying a know good part is the easiest.