I let my stepson borrow my 87 4Runner and he took it to the OHV park, For whatever reason he removed the red top battery to use in his friends. When he put it back in he didn't secure it and went bouncing around. The battery of course moved... a lot and shorted against the hood. Now it has a constant random miss. I was out of town and so my buddy has it at his house. The says he changed the plug wires and it seemed to help but other than that he is thinking the ignitor. Does anyone have any other reasonable places to start? Everything is working just constantly missing.

Thanks

 

Are all of the fuses in tact?

 

A sketchy igniter can do that, but it's an expensive part to replace on spec (and there's no way to accurately test the igniter).

I'd use a timing light to see if the miss is caused by missing spark. And I'd pull the plug wires one at a time to see if the miss is limited to a single cylinder.