Ok yesterday I changed out the ignition switch and the starter relay and solved the problem of the engine turning over on its own but it still won't start any idea what it cod be? I also just changed out the spark plugs
do you have spark coming from the end of the coil wire that goes to the top of the distributor if you set it 1/4" from some metal when cranking?
their are several tests that you need to do. the one i asked about above. you need to see if you have voltage on the positive post of the coil when the key is on and when the motor is cranking. does your car have points still?
Yes, start at the end of the diagnostic process that yields the most info. In this case, work from secondary coil backtracking until you have the voltage that belongs there. You are not allowed to say, "I don't know" when you could figure it out. You have to know how something works in order to fix it.
Yes, you want to start with the secondary and work back. Take a #2 phillips screwdriver (medium size) with a plastic handle and insert it into the end of the coil wire that you have detached from the center of the distributor. Hold it so the screwdriver shaft is 1/4" away from a bare metal surface which is a good reliable ground and have someone crank the engine while you observe the quality of the spark that jumps the gap (thick blue, thready orange, or none at all). If you don't have someone helping you, you can often set it up so that the screwdriver is resting such that the shaft is 1/4" from a ground that allows you to see it through the windshield under the edge of the open hood. You can substitute a long spark plug wire for the coil wire if you need more length so that you can see the screwdriver shaft. Is there any spark there? If so, you work downstream through the secondary (rotor, cap, plugs). use the same method but with the coil wire plugged back in to the distributor, then check the spark plug-end of a plug wire: if good spark, then your plugs are most likely fuel-fouled (which is going to be the case no matter what the diagnosis turns out to be because you've now been cranking it repeatedly with fuel dumping in but no spark). If no spark, then test the coil wire (with an ohmeter, substitute a known good coil wire, or use one of the plug wires to substitute for the coil wire in the test). Then you would test the coil windings for continuity and proper resistance in the windings (specs in repair manual)...or, if you have a known good coil that is the same type (internal vs external ballast resistor versions), then try it and check for start. Don't just go and buy one thinking you'll return it if that wasn't the problem because most stores won't accept returns on electrical parts. Do those tests and post the results. It could be something as simple as the carbon button inside the distributor cap at the center being broken, the rotor cracked letting the secondary high voltage go to ground to the distributor shaft under the rotor, crack in the cap, bad coil wire, etc). There is a diagnosis, don't just go throwing parts at it until the problem is identified. If that checks out but still no spark so far, then go toward the primary ignition system.
