1977 No spark!
Thread Starter
8th Gear
Joined: Aug 2015
Posts: 8
Likes: 0
1977 No spark!
I bought a 77 a few months ago. Put a few hundred mile on it and ran great. 64k on it. Driving to the store last week just died. Like it ran out of fuel. Had it towed home and I have no spark. Have read all the posts I can find on the subject. Have replaced the cap and rotor, the coil and had the module tested at autozone and it was good.
I have power at the red wire to the cap. It does go down to the 9v range when cranking, so I jumped a wire as suggested from the alternator to the cap. Nothing. Disconnected the brown tach wire still nothing. Any direction from here would be greatly appreciated. Love the forum btw..
I have power at the red wire to the cap. It does go down to the 9v range when cranking, so I jumped a wire as suggested from the alternator to the cap. Nothing. Disconnected the brown tach wire still nothing. Any direction from here would be greatly appreciated. Love the forum btw..
Drifting
Joined: May 2012
Posts: 1,353
Likes: 44
From: Calgary Alberta
Have you tested the coil, even though I think you said it was new along with the cap and rotor - those apparently can be bad right out of the box sometimes.
Only other thing I can think of is the ignition switch might not be supplying full power in the crank position.
Only other thing I can think of is the ignition switch might not be supplying full power in the crank position.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Usually it's the module, and no matter what the guys at the Zone said, I would try a new Delco unit first.
The only part left is the pick up coil. To save pages of posting, you-tube has some good videos on this.
Type in GM HEI troubleshoot.
Let us know what you find.
The only part left is the pick up coil. To save pages of posting, you-tube has some good videos on this.
Type in GM HEI troubleshoot.
Let us know what you find.
Burning Brakes
Joined: Sep 2009
Posts: 1,003
Likes: 48
From: hickory NC
C4 of Year Finalist (appearance mods) 2019
2017 C4 of Year Finalist
WOW.Went thru the EXACT same thing a couple weeks ago. Checked and rechecked everything.
Back in the spring I bought a new distributor and it had a 1 yr. warranty. Emailed the guy I got it from and he sent me a new one. Stabbed it in and it fired right up.
One thing you could check is the connector in the harness going to the starter, check the connections there. (If your year has one)
Good luck. And if you find what's wrong, Please let us know. Drives me nuts not knowing what caused it.
Back in the spring I bought a new distributor and it had a 1 yr. warranty. Emailed the guy I got it from and he sent me a new one. Stabbed it in and it fired right up.
One thing you could check is the connector in the harness going to the starter, check the connections there. (If your year has one)
Good luck. And if you find what's wrong, Please let us know. Drives me nuts not knowing what caused it.
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Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
I have found many "module" failures weren't the module failing at all but rather loose connections AT the module. So I suggest squeezing the 1/4" female spade terminals a bit so they plug into the module a lot tighter and try it. That may solve your problem for no expense.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
For the next guy- If you connect a 12v testlight to the TACH terminal on the cap after you unplug the tach, and crank, the testlight will blink if the module and pickup coil are doing their job. Quick and dirty test for module and pickup coil.