Volvo: 240 engine miss, mass air meter, volvo 240 gl

Question
My daughter has a 1981 volvo 240 GL that has been driving me crazy for weeks trying to locate the source of a miss, it sputters and acts like there's water in the fuel and then occasionally it will run absolutely perfect for a little while and then run like crap again. The ignition wires cap, rotor, and plugs are new and I replaced 1 cracked vacuum line and checked all the rest, compression is fine. I'm pretty sure it's a fuel delivery problem, bad injectors? please help before I lose it.  

Answer
I would check all the injectors for clogs, as well as the fuel filter.  Also check to make sure both the in-tank fuel pump and main pump are working.  Also check the knock position sensor and mass air meter.  If either of those fail, it causes the engine to run rich and very rough.  Good luck!