Ok... when I'm at a dead stop and jump on it, the tach rockets to ~4k in roughly a second, then drops back down to ~2k (whatever the true reading is) and then climbs up as it normally should. When I slowly accelerate, the problem doesn't occur--it's only when I step on it. It's perfectly accurate at all other times.

I'm also getting a code 42. Everyone says that the most common culprit there is the timing bypass connector, but that isn't the problem here.

Now, the EST module itself is in the distributor, right? And the tach gets its reading from the bypass coil in there...? How close to each other are these two pieces? I've never pulled apart one of these distributors, so I'm clueless here (I'm 17, give me a break). Are the two pieces close enough to each other that something could go wrong and cause a spark, damaging the pickup coil and the EST module? Or would something else have to get damaged in the process? Is it even possible?

Basically, I'm trying to find out if I should be pulling apart the distributor or if there's something else to check first (for either the code 42 or the jumpy tach).

Camaro--:rockon: Car almost as old as I am--

 

The tach reads from the negative side of the coil (white wire). Certain years apparently had an inline tach filter on that wire (I've never seen one myself) which I've read sometimes causes problems. Not much help I know but I've yet to have any tach problems to fix myself, yet :knock on wood: