ULTIMATE RICER! jittery tacho

[GU357]

Did the most ricer mod i could think of just today.
I installed a Racing tacho, with a SHFIT LIGHT!!!

long story short, after vtec (5k upward) the tacho responds all funny instead of moving smoothly through the range it moves in a jittery manner.

anyone know what would cause this??
i got the tach signal from the original tacho (just cut it and fed it to the new tacho instead).
And for the illumination i just ran it at the same time as power so the light is always on (dont think that should affect it, but maybe)

anyone know whats wrong am i meant to run a new cable from the coil and not use the existing one or what?
or just a dodgy tacho?

[CivicEGSI]

SH-Fit light. too much vtac probably

[eg5civic]

yeah it might not be vtec compatible or
maybe your car revs faster than the tacho can handle.

On topic, taking a guess as i have no real knowledge on installing a tacho but if its got a ground running from it, is it grounded properly, ie getting a good connection

[EKVTIR-T]

Does it have a setting for 4/6/8 cylinder?

[GU357]

yeh, ive selected 4 cylinder.
its so wierd, good until about 5k rpm. and then the revs kind of freze then move up in jumps.
might just disconnect it and run the stock tacho with the wrong redline but atleast it reads more normally.

but still if anyone knows wtf is going wrong i would like to make use of this retarded thing

[EKVTIR-T]

Apparently the signal from the ecu inot cluster is the wrong 12v signal for the tach

Run the tachos green/rpm signal wire to the blue wire on dizzy

[GU357]

ahh so the one behind the cluster isnt a good source?

ill try splice onto the Blue Dizzy wire.
and get a pic.

[EKVTIR-T]

The blue wire runs through the firewall up to there anyway so see if you can find it

[GU357]

i soldered to the one straight out the dizzy.

still not working, conclusion is that the tachos rubbish.

[curtis265]

Maybe a bad taco.

[Alexplicit]

You need to plug your iPhone into your ecu, and disable your vtak, and you must speed limit the car to warp 9... Having it on warp 10 will cause many issues including your Honda badge to turn into a chev badge.

On a serious note, a jumping tach is usually a bad earth.

Make sure you have an earth of its own, on a clean metal surface.

[GU357]

Yeh, I contacted the company they say they will replace the item.

dammit now I feel like tacos....