I squirted oil in the Cyl and the PSi stayed at 50.  I'm thinking exhaust valve.  i read that exh manifold leaks will cause valves to burn and this volvo mainfold gasket leaked big time.   I'm thinking of driving around on 3 cly's.   Is that a real bad Idea?,  Sc

Thx Travis.  Its been a heck of a holiday.  Volvo ,  changeing a saab 900 clutch slave ( which has been a total PIA,  then the Acura brake lights quit working

I went around the block in my Volvo 3 Cyl.  Not much pep but it got up a hill and went 45 mph.  I'm torn between driving it this way till it dies,  or parking it and fixing the valve.

With no gas in the 4th,  I can't under stand why it runs worse when i plug the spark plug wire up. 

Victory.. Sort of...   I had an old Bosch
 distributor cap laying around. and traded it with the new one I installed a month ago.   For some reason it ran a little better and the spark jumping between 3 and 4 isolated Better.   Now when I jerked a plug wire off I could tell which cyl was working or not. Found a bad plug, stuck in an old worn plug in its place.  Runs like a 20 year old worn out volvo should.  Thanks for you help,  I need to work on that low compression in 4 now.  Sc