QuestionPeriodically, my '69 mach 1 does not start easily and other times it fires right up. When it won't start it turns but does not sound like it is getting spark. Does this sound like an electrical (wiring) issue or a mechanical (starter etc)? Can you point me in the right direction? Thank you in advance.
AnswerWe can easily narrow down the possibilities for you.
Since you can hear the engine cranking when you try to start it, you know there is nothing wrong with the starter or the "crank the engine" portion of the ignition switch, and there is no mechanical problem with the engine.
We still don't know if the failure to start is due to a lack of fuel or spark, however, but there is an easy way to tell. You need to get a small amount of gasoline, and the next time the car won't start, remove the lid from the air cleaner temporarily, and pour about 1 ounce of gas down the front barrel of the carburetor. Then, re-install the air cleaner lid (to avoid any danger from the gas) and then quickly try to start the car. If it starts immediately now, you know your problem was lack of fuel.
The possible causes of this problem are very large in number. The most likely thing is that the car has just been sitting undriven for so long that the gas has evaporated from the carburetor, and you could have started it if you continued cranking longer, as the fuel pump would finally refill the carburetor. If this is your situation, check for gas smell in the garage after you park the car, you may have a leak from the carburetor that is causing an empty float bowl in the carburetor.
If it still did not start when you put gas into the carburetor, I suspect your problem is related to your ignition system. If the car still has the original ignition system, you can visually inspect the small wires (not the spark plug wires) that go into the side of the distributor and the small wires on the coil to see if anything is loose there. If so, fix that and your problem may be gone.
Another thing to try, when you have determined that the problem is lack of spark, is to temporarily connect a separate wire from the + terminal of the battery to the + terminal of the coil - (there will be a minor spark, but it won't hurt you, it's only 12 volts). Now see if the car will start - if it does, your problem is likely in the ignition switch. You must remove the temporary wire to turn off the engine (you have just learned how to "hot wire" a car!). In an emergency, you can even drive the car with this wire in place, but you cannot leave it that way for long, as it is bypassing the ballast resistor, which will cause rapid wearout of the ignition points.
If none of the above seems to help, you will have to take it to someone with an engine analyser to track it down further.
Dick
