firing question?h

[brian.b]

hey guy i left my car setting out side at my uncles house while i had cut my finger off i really couldnt mess with it,,well a few days ago i came to start it and take her home well it would hit and the starter would kick out ,,so i cleaned the plugs and the points but still it would hit after 2 or three times,,i checked the plug for fire ,,i put a screwdriver in the plug wire and held it from the head and it looks like it only fires every 2 or 3 revs is that normal,,,,what could be the problem,,,,any help would be greatly appreciated.

[dpledger]

A number of possibilities, involving the coil and distributor cap and capacitor. Would help if you could verify that all plugs are missing about the same. If this were the case the coil or would become the major suspects. the former of  putting out a subpar voltage. This could be because the coil itself is degrading, or there is resistance in the circuit supplying voltage to the coil. The manual specifies the resistance across the coil terminals (about 1.2 ohms I recall, )and one can measure the voltage across it with a VOM (it should be essentially battery voltage.) High resistance would require coil replacement, low voltage means there is a resistive connection or starter switch

Could also be a worn rotor or distributor cap- inspect the inside of the cap to see if the center button or plug contacts are overly worn or there are carbon tracks. An overly worn rotor will have a "melted" appearance on the metal. Replace in any case. A capacitor failure would be unusual, but not unheard of. Hard to check so replace if nothing else is found amiss. Another possibility is a partial or intermittent short inside the distributor between the battery voltage and something else.

I'd start by inspecting the cap and distributor components, then making the voltage checks. Electrical misfires generally quickly make themselves apparent as charred or melted areas.

If only some plugs are misfiring, it could be burning of the contacts in the cap, which is readily apparent.

[dpledger]

To clarify a point in my above post, I neglected to say that when measuring voltage across the circuit a likely cause of a low voltage could be degraded ignition points. Have the points closed and measure the resistance across them with a VOM. Should be zero. Still another possibility is incorrect point gap. If the little contact arm is worn the points won't separate correctly and spark will be degraded.

Lots of possibilities....

[brian.b]

thank you very much for your help i will check these things and let you know what i find...