tacho needle going crazy

Anthiron The Baja Rejuvenation Begins

4,936 posts · joined Oct 2003 · 10 Oct 2005, 1:07 pm

#415868

when i first installed my speco tacho into my baja it worked great however i remember reading in the paper work that came with it that they sometimes experienced problems with old bosch ignitions found in volkswagens. they actually mentioned the make but everything was fine so i didnt worry.

i have since lost this paper work

now. about 6 months down the track its started to develop an annoying habit of flicking all over the joint. u can still sorta use it as it tends to flick up and down by about 1000 revs depending on where the needle is. usually flicks from 1000 to 2000 when idling.

engine is running fine and the same as always. what could have caused this?

is my tacho just faulty?

nick

62/60 model bug eye baja bug, (Full Build in Progress)
1974 Chevrolet Luv
1970 MK2 Ford Cortina GT
1979 Yamaha RX125 Two Stroke tracker project.
2004 Harley Davidson Sportster XL Custom

kombikim disfunctionally capable

1,521 posts · joined Dec 2002 · 10 Oct 2005, 1:52 pm

#415877

quiet often it can just be a tiny leak of current where the terminals connect to coil, the spark or spikes in voltage causing needle to fluctuate, make sure all the terminals are tight, & the coil is very clean, step 2 is in dark preferably with blanket over open hood & your head, & engine running, see if you can see any sparks anywhere

Please, I need drivers side window regulator (winder mechanism) for my '54

VWCOOL 23 Windows of Awesome

5,158 posts · joined Jun 2003 · 10 Oct 2005, 8:47 pm

#416049

kombikim wrote:quiet often it can just be a tiny leak of current where the terminals connect to coil, the spark or spikes in voltage causing needle to fluctuate, make sure all the terminals are tight, & the coil is very clean, step 2 is in dark preferably with blanket over open hood & your head, & engine running, see if you can see any sparks anywhere

Yep - mine was doing this last week. Also minor misfire at 5500+ rpm. Loose (+) wire on the dissy - I added a new spade terminal and now no worries all the way to 7K

Pay your debts, CxxT

dragbug Wolfsburg Wizard

609 posts · joined Sep 2004 · 10 Oct 2005, 9:16 pm

#416073

I sell Speco and have installed them to a few dubs now.
Run a inline diode between the sender wire off the coil and the tacho.
Should sort it straight away.
40 cents max from any dick smith or tandy store.

"O.S.K"
We make it happen!

Mad Manx KombiKroozin

456 posts · joined Aug 2002 · 10 Oct 2005, 9:19 pm

#416077

replace your condenser

- '71 Kombi (Died 24/11/05😢 ) - '65 manx (smick) -'63 beetle (bent) -'73 Singlecab (new to the stable)

dragbug Wolfsburg Wizard

609 posts · joined Sep 2004 · 10 Oct 2005, 9:23 pm

#416082

Could be,........
The install sheets actually suggest if you are setting them up to run with a vw engine,
You might need the diode to stop needle fluctuating.

"O.S.K"
We make it happen!

vw54 Administrator Always Waiting 4 Friday

16,723 posts · joined Aug 2002 · 11 Oct 2005, 7:26 am

#416235

Put a loop in the wire that attaches to the coil end or dissy end this will stop the fluctations

I read it on FACEBOOK so it must be true

http://forums.aussieveedubbers.com/viewtopic.php?tid=91278&page=1#pid848630

http://forums.aussieveedubbers.com/viewtopic.php?tid=63561&page=1#pid624099

http://forums.aussieveedubbers.com/viewtopic.php?tid=4832&page=1#pid452603

http://forums.aussieveedubbers.com/viewtopic.php?tid=60650&page=1#pid574409

kroozzn63 Bishop of Volkswagenism

3,005 posts · joined Jan 2004 · 11 Oct 2005, 7:45 am

#416247

stop reving it "i had to say it" to compensate for my lack of knowhow

show us your gates

PUNCH_BUG Slammed & Awesome Dubber

93 posts · joined Oct 2005 · 11 Oct 2005, 9:36 pm

#416492

Dragbug. what you said to do with the diode, have you done that to other gauges as well? e.g. fuel and spedo that run off senders?