3 out of 4

[glennn]

my car is an auto and is idleing about 700 and is very rough, when i put it into drive rpm goes down then stops , i listen to the 4 injectors with a scew driver and its sounds ok i then check each spark plug for spark also ok but if i remove the plug terminal for each injector, 3 out of 4 just about stalls the engine, number one cylinder if i remove electrical plug to injector it makes no difference to the engine rpm and sound , i swapped spark plugs and injector to eliminate problem still numbwer 1 cylinder seems tobe and maybehas no compresson, i dont have a comprresion tester , i have changed the head gasket preaviously after it overheated but is there anyway 1 out of 3 has no compresson unless the rings were blown?