Best practice for 1st gen ingnition system?

[dyoungre]

Jake,
Does your tach jump around at the same time that the signal on your data jump? Is there misfire? If not, then what Jim said is probably root cause - simply noise on your tach signal. If the tach is erratic as well, or you can feel misses that go along with the noise, then I'd check the slop in your distributor. They do wear, and can cause erratic pickup signals.

[lateapex911]

OK, guys, thanks for the responses.

here's the skinny. Tach wire was run neatly along with other wires. As the cars seems as powerful as any other NE RX-7, I couldn't immediately assume actual ignition issues.

So, I undid the neat harness, and left it flopping about. Problem instantly solved! Viola! Seems being messy has it's advantages?

(I'll make it neat, but a respectful distance AWAY from the mean wires, or I'll go shielded.) Thanks for the suggestions, and James gets a free beer when he comes to CT, as he hit it first.

And if you ever come to the track Dave, I'll give you one too!

[dyoungre]

Plan now is to try to make it to the Pocono double in July, since it is only an hour and a half from home. It's amazing how busy the twins keep us.