no spark
Thread Starter
Le Mans Master
Joined: Oct 2006
Posts: 8,941
Likes: 35
From: El Cajon California
no spark
Took the 78 out for errands, it started to miss, after I got it home it would not start.
I pulled out a plug connected the wire and cranked - no spark
I put my test light on the red batt wire on the distributor
Turned the key and the light lite, it has power
Is the distributor bad?
I pulled out a plug connected the wire and cranked - no spark
I put my test light on the red batt wire on the distributor
Turned the key and the light lite, it has power
Is the distributor bad?
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Pull your tach wire off the distributor and plug your testlight between that terminal and a good ground. Crank, if the light blinks the module and pickup coil are OK. That makes it either the cap/rotor or the coil itself. No blink, the module is an easy fix, the pickup coil you have to pull the distributor apart to change.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Look for a burned spot in the center of the rotor- that's the usual place. The coil, GM has a test for it with a meter but I don't recall all of it. And coils are not all that expensive anyway. I do recall something about checking from the center of the coil to the ground on the coil itself, and then from the power input of the coil to the tach lead, and then both of those to the ground. Someone may chime in with the GM instructions.
Drifting
Joined: Sep 2010
Posts: 1,412
Likes: 50
From: Laguna Niguel California
Here's another thought. I recently had a similar problem. After some thought, I cleaned the contact surface on the end of the power wire to the distributor cap. Haven't had a problem since. Face it the wire contacts are 40 years old and oxidation does happen. New contacts are available on-line from hay-wire, I think that's the name.
