Help me again

Well here is tha deal on tha 92 cavalier RS it's a 2.2 liter and when I got it, it would not start at all I put a new batter in it I took tha sparks plugs out and done a comperssion check only 2 cylinder are 100psi and over tha other 2 are like 50 and a little under 50 what would cause tha compression to be so low I put a couple drops of gasoline in tha spark plug holes and then put the pulgs back in a collected tha wiring and tried to start it it acts like it wants to start but it can start on 2 cylinders over 100psi can it we also put injection cleaner in tha throttlebody and tried to start it with tha throttle open I checked to fuel pump and its good so what else could it be could you tell me if there is a place and where to hook up gauge so I can do a fuel compression check

thx