Questioni have a 1971 spitfire and it won't start or try to start, it just keeps cranking. it has spark, the timing is right, and its getting fuel. any ideas what might be the problem?
Thank you.
AnswerHi Charles,
All piston engines only require 3 things to run. compression, fire and fuel with conditions on each.
Compression --- There must be at least 125 PSI compression on each cylinder and there must not be a lot of difference between any cylinder. This MUST be tested first and with the throttle open and turned over at least 4 or 5 revolutions on each cylinder test. If you don't have a compression gauge, they are not expensive and can be bought at most any auto parts store or even at Wall Mart.
Fire --- You must have a good spark to the plugs and at the correct time. A rough test if you don't have a scope available to you is to just let a spark jump to the head or any metal part on the engine and the spark must be thick and colored blue. The timing must be set to specs and the firing order in the cap must be correct (1,3,4,2)
Fuel --- The fuel must be a good fuel and available to the combustion chamber. A simple but effective test is to spray starter fluid in the intake when trying to start to see if it tries to start and run for a second or two. WD-40 spray works well too.
One of these must show up what is wrong. Don't skip anything.
Howard
