Swinging tacho

[gdee123]

After accelerating, tacho oscillates +/- 1000 rpm and steadies down after 2 - 3 seconds to a stable value. No other issues. Is this normal?, I haven't checked anything yet, pending replies.

Garrett

'73 2.4S Targa

[gruen911]

Hi Garrett,
That isn't normal. If you know your gear ratios, and you know that your speedomoter is accurate, you might check to see whether it is still accurate and just bouncy, or if it needs a rebuild.
Tacho bounce could also be due to having a non compatible CD Box. For instance, switching out the original Bosch unit for an aftermarket unit like Permatine or MSD could cause the tacho to bounce or not work at all. You might also check the ground.
Things like oil temp, speedo and revs are important, so if it were me I would ship it off to N. Hollywood Speedometer and have it checked and rebuilt. I have had all of my gauges checked and rebuilt - except the clock whivh runs slow by about 3 hours aper day. I don't even pay attention to it as long as it lights up at night and looks good...

[kenikh]

Huh. I always thought this was normal. I guess I'll have to add this to my project list.

[Chuck Miller]

Garrett,

Also check the purple wire connection (tach) on the side of the distributor... making sure both sides of the spade connector is clean and the connection is tight.

Cheers,

[GreenT]

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[gdee123]

Thanks, guys.

I have checked out the connections, that purple striped lead was quite loose at the spade connection: fixed. Its piggybacked onto a black lead, is this right?

I have also cheched points gap, I await getting a DVM for next weekend to check out electrics more thoroughly. Then on to instruments if necessary.

I'll be back