Crazy Tach

KensSpider · Post by **KensSpider** » Thu Sep 21, 2006 1:41 am

On my "new to me" 1975 Spider, I notice that the electronic tach seems to move around a lot more than the engine does. It can jump up and down by a 1,000 rpm at random. It does occasionally seem to steady itself when I am cruising along, but any sort of gear change or change in the engine causes some wild swings.

Is this considered to be "normal"?

If not, is there anything I should be looking for in particular?

Thanks.

Ken

So Cal Mark · Post by **So Cal Mark** » Thu Sep 21, 2006 11:14 am

no, that's not normal. The tach should accurately indicate engine rpm. Check the connections at the coil, but tachs do sometimes fail

KensSpider · Post by **KensSpider** » Fri Sep 22, 2006 8:55 pm

Well, it looks like the connections at the coil were at least part of the problem. I cleaned them and reattached, and went for a spin and the tach was significantly better behaved. Still a little jumping around, but 90% better.

I am wondering if I should maybe replace the coil (it looks like it's been around for a LONG time ...) and then clip off and reattach the spades on the wiring. Make it all new, so to speak. Hmmmm..

Thanks for setting me on the right direction!!

Ken

So Cal Mark · Post by **So Cal Mark** » Fri Sep 22, 2006 9:13 pm

have you checked the point gap?

KensSpider · Post by **KensSpider** » Sat Sep 23, 2006 12:35 am

I haven't yet delved into that kind of stuff. Two reasons ... (1) still a nice few days to drive around and I don't want to mess stuff up and, (2) I'm waiting on the postman to bring me a Haynes manual so I have a little better idea of what I am doing!

Cheers!

Ken