I got this problem startin to bug the **** outta me!

-When I'm in vtec, soon as it crosses over my tach starts bouncin back & forth all the way up. Like its loosing spark or something. The motor itself feels like its still pullin, but the tach is all over the place.

--things i've tried. Re-did all of my grounds with new connections and metal.
Also, Made sure my optima was tight as can be.. which seemed to help actually but its' not solvin the problem.

Am I just grounding out somewhere?

Just to let you know on my setup, everything is new. optima battery, accell internal coil, new ngk iridiums & wires. jdm h22..bolt ons..

what the [freak] is the deal.

 

try hooking up an external tach and see if it does the same thing, if it doesn't, you need a new cluster.. that is a very strange problem tho..

 

the gauge seems to be working properly.. just when its high rpm vtec. my bud has an external tach but i rlly don't wan2 splice into the wires less i absolutely have to. i feel like my positive terminal is loose or something, but its definitely tight.

 

i found two other threads, and mgags recommends a bad ground or bad ICM.

https://honda-tech.com/zerothread?id=2126096
https://honda-tech.com/zerothread?id=2145261

there is a blue wire near the passenger strut tower with a plug/cap on the end of it.. that is a tach connector, so you don't have to splice any wires

 

we have a plug on the driver's side of the car that has an ignition output signal, no splicing needed

 

passenger strut tower

 

thats cool, about the tach wire under the hood... convenient**

I also, agree with the grounds... I just replaced & added a few grounds.

vtec oil pressure, directly to battery
intake mani to chassis
battery ground
drivers side tower ground

After I did this, It seemd to cut out the problem, then it came back. I'm wondering if adding those extra grounds gave me any type of negative feedback. You would think, the more grounds, the better. I spent a lot of time with those wires..

 

you can see where i grounded the vtec pressure, directly to the battery. so, technically its grounded twice now. I havn't figured out if this was a good idea, or not. Just trying some things.

 

Dont know if this will help but, 2nd Generation Tegs have an issue that is quite common. Your igniter wires in your distro cap might have a poor connection. My tack in my old GS-R would bounce around like nuts when VTEC came around the corner. By some dielectric greace from Auto Zone for the connections and crimp those puppies down. Look at http://www.g2ic.com there is a tutorial.

Hope it helps.

 

oops, I had the wrong side

 

I'll try workin on the dizzy connections... That does make sense, but I just can't seem to find out why im losing power up there. I just put new plugs in last nite 2 see if it helpd, & did a valve adjustment* the car runs & idles fine. fuel pressure set at 43psi wot. im stumpd!

 

Try the external tach! Your taking things way too far before you even try the simplest test

 

well the valve adjustment was just an im bored & it's been awhile..

i'm going to try the tach,, but the way it's acting im not really thinkin its the tach.. it only acts up in vtec at wot. so i'm just doing everythin i know how to, to get it running good.

 

I had the same problem as you where my Tach would be 1k off. Car ran fine and such and I had an external tach setup and that was showing proper reading. Swapped out the cluster and problem solved

 

my buddy got a monster tach im gonna hook up 2 try and rule out the tach. I know my stock tach is probably off... as most of them are.
But: we sat down and thought about it.. and I just can't see it being the tach if its only at wot in vtec.. but i could be wrong.

--Poor signal to ignition switch
--Loose connection in a certain ground --Thermo ground maybe?

I've replaced almost all ground wires & cleaned up the stock ones I left.

 

I have the exact same problem, once I get to vtec my speedo starts to bounce wildly, I'm thinking its some kind of electrical problem.

 

I took off my battery terminals, cleaned & re-connected, AS TIGHT as I could.

Also, took off my vtec oil pressure ground, cleand & and put a new connection on it.

Took it out for a spin, and NO*** Bouncy Vtec!!

I'm assuming it was my battery terminals being not loose but apparently not tight enough! It's runnin lot smoother

 

Hmm... Maybe it was a corroded battery. O well atleast you fixed it.

Good joB!

 

yeah might of been the terminal. i cut it off the old piece & put on a gold plated one. made sure everything was niice & she's pullin all the way up top.

Note To Self:: Keep Battery Terminals Cleaned & all Tight. The bouncy vtec must be just bad ground cuttin out up top