got a bug in my tacho

[Cokeaddict]

Has anyone come across this on a GQ tacho?
It started about 2 weeks back but its not always there.
Comes and goes at will. Not a real problem though as after 26 years owning GQ's I know what revs the engine is at without the tacho.
I am hoping its a simple fix.
Hope someone has come across it before and can help me identify the cause.
Thanks in advance.
http://vid128.photobucket.com/albums/p1 ... 3ec084.mp4

[V8Patrol]

Not being up with GQ's ..... electrical driven tacho or cable ???

Electrical would suggest a loose connector / faulty earth / or a broken wire in the feed loom......
Have you made any under bonnet or under dash changes of late that may have disturbed things ??

Cable would suggest a kinked cable, my speedo drive does this at low speed, an impact with scrub debris put a big kink in the cable and the 'jump' was initially quite bad, after I physically straightened it,.... it was almost gone but still does a tiny jump up to ~15kph, once over that she's as steady as a rock.

[Cokeaddict]

Its electric.
i did a very rough corrigated drive which may have vibrated wires loose.
i will take the cluster out and have a look.
thanks for the input.

[Lepa]

check where the wires come over the front of the motor passed the thermostat. mine came off their holdigns and were flopping against the fan. haven't had a tacho for a long time as as you said - drive them long enough you have a pretty good idea what rpm going on

[blackops]

had this taco prob used to twich alot, radom miss.. like ,was told alsorts blocked carby secondary jets ,dizzy /cracked cap lose earth etc... ended up binging a head light relay at the fixed fuse board,in fuse box under dash .. cause i had wired up new spoties ...couldnt handle the extra amp drain played absolute havoc on everything took me 5years to find and about $ 2000 later...hope this helps some other poor barstard:0

[Cokeaddict]

Good to know thanks. Mine still does it but only about 10% of the time now compared to 90% before. I found 2 issues...
1st was the plug that sits near the thermostat housing had loose wires and
2nd was the actual magnetic sensor in the front of the motor. Took that out and cleaned it dry (had lots of shit on it) Resealed it and from there on, its much better than before. Still not 100% but heaps better. So I thnk there could still be some wire damage somewhere in that feed. Will check it all out again another time.