72 TA : New Project

[njsteve]

Today's lesson is the principle of Occam's Razor or in Latin, Lex Parsimoniae, which translates to "the simplest explanation is usually the correct one".

I have been chasing down a tachometer gremlin for a while trying to figure out why the tach would not rev beyond 4000 rpm even when the engine was obviously going faster that that. Also, when the engine was cold, the tach would read double it's actual engine reading.

Well, after fiddling around, running extra tach leads to other tachs to compare readings, checking the distributor leads, checking point dwell... I was about to pull the coil and change that.

Guess what...the coil wire was not fully seated into the top of the coil and all this time, the voltage was just jumping across which, while powering the ignition system, was wreaking havoc with the tach accuracy.

So I pulled the coil wire, cleaned the terminal ends, pulled the boots way up and made darn sure both terminals were locked into the coil and the distributor. And now the tach reads correctly.

So let that be a lesson to everyone - check the simple, stupid stuff first. [img]<<GRAEMLIN_URL>>/scholar.gif[/img]