I have an 81 z28 with a 350 and a holley 4bbl carb. I took it all apart a week or so ago just to clean it, put it back together, and fire shot out of the top of the carb. i assumed that i moved the distributor and threw off the timing, or it was the carb cleaner i used to clean out the intake manifold. Either way, I didnt have time to deal with it just then. I got back, set the timing, and its still doing the whole dragon thing. Incidentally, when I pulled off the rocker covers to look at the valves and pushrods, it was arcing out, which confused the hell out of me because theres no current running to the rocker covers. Anyhow, i need someone to tell me mystupid selfhooked a wire up wrong or something and I dont need new heads.

 

You had electrical arc sparking from your valve covers? If that's the case there's a serious problem with grounding. Do you have a ground strap from the engine block to the chasis?

 

Theres one running from the passengers side rear of the block to the firewall, and a ground cable on the alternator. I didnt see anything obvious grounding out on the block, but my wiring has been all gaggled over the years, I need to eventually just rip it all out and do it over.

 

Check your spark wires and make sure none of them have been rubbing against headers or have abraded somewhere. Also make sure your air cleaner isn't rubbing against the distributor boots. If they're cheap wires they can easily spark jump through the insulator. I learned that a while back while working on a car and the damn thing shocked the **** out of me while I was doing timing. Make sure that none of your spark plug wires cross over each other especially if they're in firing order (i.e. two wires next to each other crossing or wrapping around each other). Make sure the boots are pointing away from one another also.

I know what you mean about the wiring. The guy who owned mine before me did one heck of a job at mangling it. I had dead connections just terminated and cut without being taped off or pulled. I find new ones everytime I do something new with the electrical it seems. If I get the chance soon there's a whole new wiring harness and fuseblock being purchased and going in.