Rev counter drops momentarily then okay?

[TVR Beaver]

Went for a spin today, about 60 miles and I noticed a couple of times the Rev counter drop momentarily and them bounce straight back and be fine for the next 30 miles or so?..

no other issues..

any ideas?..

I have checked the coil connections etc and all okay...

Is there a rev counter control box.. or could be in the gauge itself??

[TVR Beaver]

Any thoughts ?

[rigga]

I thought it took it's pick up from the coil too ....

[PeteGriff]

Hi TVRBeaver, did you feel the car shunt or hesitate at all? If not it could well be electrical glitches. I have not had to delve into the Griffs tacho since I have had it so cannot comment from experience, but usually they are driven from inputs from the distributer or a rotational sender unit. If none of thes at fault could be internal glitching of the tacho. Might be worth just leaving it and keeping an eye, it may go away or get worse, then you can start fault finding and pulling stuff out....

[SteveSPG]

mine did that once or twice before i modified the wiring for the ls engine, since then no issues, so in my case it was wiring causing the problem somewhere

[TVR Beaver]

Cheers guys. No other glitch or shunt. Just the needle droped down so either wire to the tacho or internal in the unit I guess. So there is no drive box for them. Just straight to the coil. Will keep a watch on it. Cheers