Hey everyone, the 302 in my 69 z28 has been acting up recently. It has had issues breaking up past 5k rpm. Ive done the basics such as replaced cap and rotor, replaced ignition coil, checked valve lash, and done a compression test. Nothing has cleared up the issue.

Besides breaking up at high rpm, it would also backfire through the carb if you give it gas when idling. I also discovered that while checking for compression using my bump starter, the coil was arcing from the output to the ground on the coil. Maybe that could be the issue? Hopefully someone can point me in the right direction.

 

With the engine running, does it look like a Frankenstein laboratory when the lights are out?
I'd replace the plug and coil wires first, before suspecting something else. Spark jumping to ground will make the ignition cut out.
Btw, I didn't know you had a 69, let alone a Z/28.

 

No she looks normal when running

I know the plug wires are old, so maybe I'll try replacing those. I also have a stock coil laying around I might give a shot. But yes I do have one Here are some pics for you!

 

Oh nice. Now I recall you showing the 69 a while ago......long enough for me to forget!
Seems to me I may have mentioned something about the need for a hood adjustment on the passenger side.

 

Coil is definately suspect, had a similar problem with my 400 in my boat around 5k it was fluttering and would die sometimes when at operating temperature. I replaced the coil and started running sweet again. I am a newbie and will post my album soon, good luck! hope this helps.