Intermittent Starting Issue Stock '77

[Go Devil]

1977 Stock 302 in good mechanical shape. Intermittently engine will not start while cranking but fires when key is released in the run position after starter stops. It has not let me down but I would like to repair the problem. I replaced the ignition switch witha Napa brand but the problem persists usually 3-4 times consecutively every 10 starts. Any advice would be well received.

 

[Bronco Junkie]

Does it fire up cold OK?

 

[Go Devil]

Always starts really easy just 35% of the time in the run position instead of while cranking.

 

[YNOTBOB2007]

I had a similar problem that was related to my resistor wire. It should have been bypassed when I installed the HEI distributor as it was reducing voltage when I needed the full 12 volts.

 

[Broncobowsher]

There is a bypass wire brom the starter solenoid to the ignition. On the solenoid it is the little terminal usually marked with an "I". That post should go hot while cranking. That post bypasses the ballast resistor to give an extra jolt to the ignition system to help make up for the voltage drop while cranking.

If there is a fault with that system you can get an intermittent crank with no spark just like you describe.

 

[Go Devil]

Thanks for the info, I'll check out the wiring and the solenoid tonight.

 

[Go Devil]

New solenoid fixed my issue, thanks for the replies.