Hi all
Electrics are not my strong point - any ideas welcome.

I've wired up my tacho as per the diagram, when I start the engine (pinto) the tacho reads approx 6000-7000 rpm on tick over.

The gauge is from a cortina - smiths RVI 2413/co - 4cyl neg earth

reads zero with ignition on and engine not running

no elec ignition - using points


[Edited on 9/9/08 by peterparsons]

hmm is there a switch for selecting the number of cyclinders?

The RVI tacho's are generally not compatible with electronic ignition (other than very basic "transistor assisted" types). Does your Pinto have points?

Is is correctly reading 0 RPM with just the igntion on but engine not running?

quote:

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Originally posted by Mr Whippy
hmm is there a switch for selecting the number of cyclinders?

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hmm its a pinto anyway, never broke one yet from thrashing it

no, not switchable - 4 cylinder neg earth

yes reads zero with ign on and engine not running

no elec ign - using points

[Edited on 9/9/08 by peterparsons]

[Edited on 9/9/08 by peterparsons]

loose connection then maybe, is the needle steady or flickering about? if it is then I'd suspect that might me the cause, otherwise not sure, is it one of those wrap round a lead type or just connected to the + wire for the points?

Does the tickover sound fast, like a F1 car maybe Does it read from the coil + ?

what diagram?

can you post photo of rear of speedo?

the RV1 smiths came in different flavours -t he very early ones use the loop of wire connected to coil as a primary for the internal transformer; later ones take a wire from the + of the coil.

If you are running points, then are you sure the condenser is fitted and working?

It does sound like you are getting too many pulses, about 10 x.

Do you know if the rev counter is working?

so how much do you want for this apparently super tuned pinto?

Does it read higher (even higher) when you rev ? If so it's sort of working. I'll have to check with one on my bench but I have a feeling there is a calibration pot but don't touch it yet (unless you already have ). It sounds as if there is an earth off, either in the external connections or internally.

There should be 4 connections - sense loop in, sense loop out, Ign +ve and earth -ve. Don't assume that connecting the instrument case to earth will do it - you need a solid connection to the -ve terminal.

[Edited on 9/9/08 by Macbeast]

NO CHANGE TO THE GAUGE IF i REV THE ENGINE !
JUST READS CONSTANT