I am having starting issues following cam belt failure and engine rebuild. Compressions are 20 bar on 3 cylinders but only 14 bar on one. Having removed the head to check the valves all seems ok with no leaks from valve seats. Protrusion visually looks ok. Would this cause a non-start as ECU doesn't see acceptable ratio on a single cylinder?Any data on expected cylinder pressure would be great.

Thanks

Colin