About 30k miles ago I upgraded the distributor in my 350 El Camino to an HEI style unit of generic brand. It's been running great all these years. Yesterday the battery finally needed replacing. Today I install the new battery, attempt to start, and now suddenly have no spark. I confirm the HEI Batt lead is getting 12V, so I remove the coil and test it. Infinite resistance between button and leads, so I guess the coil is bad. Then I remove the cap and rotor and find this. I also confirmed the pickup coil has proper resistance ~850 ohms.
- What failed first?
- Did the bad coil burn up the cap or vice-versa?
- Why would the coil decide to fail when replacing the battery?
- Is this just coincidence?
- Anyone recommend good quality replacements? Looking at MSD or Summit brand.
I'd say the carbon brush on the center of the cap either failed, or wasn't there at all. That is arcing damage.
It was there, but it was sure worn out. I'm just surprised it would coincide with a battery replacement. And without warning. It ran great yesterday.
Fact: A Chevy will run poorly longer than most engine run at all.
The HEI rebuild kit arrived last night, so I replaced the cap, rotor, coil, HEI module, and whatever else came in the kit. Fired right up but ran very poorly. Realized I had plug wires #2 and #4 swapped. Then it ran perfectly.
I'm still confused why the coil decided to fail the moment I replaced the new battery. The distributor was installed 10 years ago, but only 40k miles or so on it.
Another oddity, now the GEN light does not illuminate. It used to light up whenever the key was on, but engine off. Almost like it's burnt out. I have 12.7 V with engine off, 14+ with engine on, so the alternator is working. I'm wondering if installing the new battery created some kind of "power surge" that blasted the GEN light bulb and ignition coil. Maybe the order of battery cable was to blame? Such as putting positive on first before the ground (which goes to engine) or vice versa. I don't know. Just glad I got my trusty Camino running again.
Well, a coil's sole purpose is to blast electricity down a wire when you disconnect something...
Maybe the coil (or do you still have a condenser) was charged when you disconnected the battery and it somehow backfired?
Also, usually the alternator won't work if the Gen light bulb goes... That light is lit up "backwards". Meaning the switched +12 comes into the light and goes to the alternator signal input. When car is on but not running the light lights up because there is no voltage at the alternator. When the alt spins, the light has +12 on both sides, so it goes out. But without voltage signal coming into the alternator, the alternator doesn't charge.
So, without a Gen light I have no idea how your alternator is working.
The magical pixies that were keeping it running are still in the old battery. The new pixies didn't have the experience to figure it out. You just needed to jump it off the old battery once so the old timers could tell the whipper snappers what they were doing wrong.
