I remember an odd story from this site, do not recall the make or model, 50’s era vehicle, truck I am thinking, but a no start condition was finally solved by, I do not recall which, horn relay or horn ballast resistor. Does your horn work? Check the timing and dwell angle.
If it “sounds like it wants to start” try this…Loosen the distributor so you can move it…Have someone crank the engine while you slowly move the distributor (advance the spark) and see how the engine responds to that…To advance the spark, turn the distributor opposite the direction the rotor turns…
Well, I lost patience and took the truck to a local shop where they told me, “We’ll get it running.” After three weeks, I got a call from the mechanic there who told me they could not get enough compression in the cylinders to get the engine to start. The engine was rebuilt about 10 months ago and ran until last March or April. I replaced all the wiring and thought that I might have missed a ground but if the engine has stopped because compression was lost, what happened?
Could it just be a timing issue? or is this going to be another rebuild?
So, what are the compression numbers?
Squirt some oil in each of cylinders and turn the engine over a couple of times. With all of the ‘nonstart’ attempts gasoline has washed even the small amount of oil on the cylinder walls and the piston rings down into the crankcase. Residual oil seals the rings to the cylinder walls and seals the sides of the ring to the piston. Once that is gone combustion mixture escapes to the crankcase easily. So by the time the spark occurs there is nothing left to burn.
Usually the spark plug(s) are over the exhaust valves. Check the cam timing by determing the degrees After Top Dead Center when the exhaust valve is 0.020 inch up. Compare that reading to the specification.
Has the distributor ever been out of the motor. It may have been replaced more then a gear or two off. If that’s the case, no amount of turning it on top will make it run. I would pull and realign it just to be sure if you have exhausted everything else. It’s not a big job.
No compression? I presume this test is done w/out the spark plugs firing, so you can eliminate ignition timing and spark quality as a cause. So most likely the poor compression means either there’s serious problems with the cylinders, piston,s and/or rings, or the valves aren’t working correctly. Is it possible the timing chain is messed up, and the valves are opening when they are supposed to be closed?
Remove the #1 spark plug. Turn the engine over by hand with your thumb over the spark-plug hole. When you feel compression, observe the timing marks and bring the engine up to TDC on #1’s compression stroke. Remove the distributor cap and verify the rotor is pointing at the #1 spark-plug wire…Remove all the plugs and give each cylinder a tablespoon of motor oil. Crank the engine a few turns with the plugs out to distribute the oil and seal the rings. Install the plugs and attempt to start the engine…The carburetor will need a working choke in order to start…