Bad Coil

[ccd3]

My 71 with a 350 crate has been pis*y about starting the last month or so. Changed the plugs, leaned out the Holley, made sure the choke was working- all the usual suspects.

Sometimes it would just get a bug in its bonnet and decide not to start. I'd fiddle with wires, check stuff, and go through the motions and it would start up. I just figured it wanted attention.

On Monday, after a 1-2 mile drive from work, I parked it in my garage. A moment later I needed to move the truck, and it wouldn;t fire. Quickly figured out there was no spark.

Thinking my HEI wasn't getting enough juice, I cleaned up my circuit by wiring directly into the fuse box- that didn;t help.

I decided I would put in the correct plugs for my Vortec heads (my bad- I ordered plugs without thinking I didn;t have stock '71 heads) Those non Vortec plugs were a sooty mess after only about 75 miles. Obviosuly that didn;t help. In the midst of getting that &^%& #3 plug out from behind my header, I dropped a sizable piece of road crud into my eye. No manner of flushing, rinsing or cussing would work it loose. it took a trip to the minor emergency clinic to get it out... and a tetenus shot. Maybe I should think about taking those safety glasses out of my tool chest next time...

Pulled the cap on my MSD dizzy. It was a mess. Contacts were very pitted. I pulled the coil and checked the coil. I *think* the ohm meter gauge was telling me the coil was "open"- but I'm not really sure. My manual was kind of vague on the subject. I think the PO put a stock coil with the MSD module.

So- I hung a new coil/cap/rotor on, turned the key and it fired instant.

My question- do coils really ever go bad? I've never had to replace one on the kazillion internal combustion engines I have owned. My understanding is that they are rock-simple. What could go wrong? I read a thread and someone stated an MSD module could fry a stock coil, but they didn't elaborate. Have ya'll heard anything like this? These are the things that I think may have contributed:

Accel plugs with a too-short reach for vortec heads
a seriously pitted dizzy cap (motor has few miles)
msd module with a stock coil


What do ya'll think. Did the coil really fix it or was it more a matter of just giving "Bess" undivided attention for a couple of hours that made her spark? (I haven't washed her in a week or so)

Thanks Folks