Is the gas tank more than 1/3 full? I replaced the two-and-a-half inches of 3/8" i.d. rubber hose between the in-tank fuel pump and the metal pick-up tube in the tank in my '84 245 GL and it solved an intermittent problem that fits your description.
Have you checked the engine wiring harness for brittle/missing insulation? The Swedes tried a more environmentally-friendly plastic insulation from '80, I think, until '87. Look at the large gray plastic connector block at the top middle of the firewall just aft of the valve cover. See any bare copper? These are notorious for causing all shorts of problems. There are many posts in the archive about replacing the harness.
Good luck!

My '84 245 had the same problem. First of all, check your engine wiring harness. Look at the large gray connector on the firewall just aft of the valve cover. See any bare copper? These harnesses are known for brittle insulation.
Next, try unplugging the oxygen sensor. It's on the exhaust just below the manifold on the right side of the car and should have three wires that connect at the right side of the firewall. Unplug the two-wire connector. That's the signal circuit. The single-wire connector is for the sensor heater. If she runs better with the oxygen sensor disconnected, then it needs to be replaced. That should be done about every 30,000 miles.
Next, with the ignition turned OFF, unplug the air mass meter (AMM). Look on the left side of the car for the accordian "snorkel" that feeds air from the filter to the throttle body. The amm is the thing attached to the left fender in about the middle of the snorkel. Pull the electrical connector (remember, iginition off) and then start her up. If she runs better, it's a bad amm.
Report back and let us know what you find.