That is more variance in compression than you would like to see, but that will not cause the problem you are having.Have you checked to see that you are getting good spark? You can remove the plugs, then stick them back in the boots with the threaded part of the plug on the engine so it can ground, away from the spark plug hole. Turn on the key and hit the starter. You should see a fat, blue spark from each plug. If the spark is weak and yellow, you are not getting enough power to the plugs. If the boots and secondary wires are really old, they may be broken inside, or the insulation may be badly cracked, both of which will prevent good spark. The boots are easy to replace. If you do, avoid resistor boots. Sometimes the ends of the wires where they go into the coil can be bad. You should be able to remove the wires (typically there is a threaded cap holding them in) and cut off about 1/4 inch and reinstall. If the wires are molded in, you are stuck with them.