between 4 and 5k my tach starts dancing and going up and down. it only happens when i get past 4k. it doesnt do it everytime but almost everytime. i try to pay attention to my digital tach to see if it changes around too but i just cant pay attention enough to tell. it doesnt look like its jumping around. i know it seemed like the shift lite on it was going off way to early the other night. this issue doesnt effect driveability buts annoying. any ideas? i unplugged the digital tach and the factory one still did it. so its not the digital tach causing it. any ideas?

 

i would prob. say your igniter.

 

hell the car doesnt do anything, and ive got msd coil and box setup. It runs fine never flinches

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ghg78 &raquo;</TD></TR><TR><TD CLASS="quote">i would prob. say your igniter.</TD></TR></TABLE><TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ghg78 &raquo;</TD></TR><TR><TD CLASS="quote">i would prob. say your igniter.</TD></TR></TABLE>

bingo

 

so whats the ignitor doing to cause this since the car isnt running any different. i need to figure out if this is serious so i wont have problems at that track soon.

 

its about to die, that's what its doing

 

well all i know, ill be cruising some somtimes the digital tach will just blank out to zero. and sit there for a minute and then kick back in. i checked its connections which its connected into a blue wire on the driver side under the hood. but the factory tach will remain doing its normal operation when this problem occurs. i unhooked the digital tach and the factory one will still lurch after 4k up to 5500 or so. and come back down but it NEVER EVER does this under 4k. one time it starting jumping between 3 and 5500ish when i revved it up there, but i havnt seen it do that **** but once. all this happening and the car wasnt even flinching. I think i may have some bad wiring connections at the ecu cause i moved the ecu around quite a bit today and it never did any of this all day after that today.

is the ignitor, the NEC board on the inside bottom of the dizzy

 

that was spoolinmatt ^^^^^^

 

im gonna try swapping out the cluster first, it doesnt seem that the digital tach is being messed with.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ghg78 &raquo;</TD></TR><TR><TD CLASS="quote">i would prob. say your igniter.</TD></TR></TABLE>

WTF are you talking about?

stuff like this reminds me as to why I do not visit the Tech forum any longer.

The igniter has NOTHING to do with your tachometer operation. The CKP sensor is what sends signal to the ECu and to the cluster for tachometer output. I think it is a black and yellow wire or a blue with black stripe wire if I am not mistaken.....I could go on Honda's ISIS website to make sure.

Anyhoo, You are probably getting a mixed signal from the CKP sensor (crank angle sensor) which is located inside the distributor. I suggest making sure that your Tach lead wire from the ECU is not making any grounds and that the aftermarket tach lead is not interfering with the signal. If that faild, check that the circut ribbon on the back of your cluster is not damaged in any way. If you find that neither one of these are your problems, feel free to PM me with further questions.

 

nevermind, both tachs are acting goofy now that ive studied them. and the oem one still acts crazy when i unplug the digital tach. im really thinking its a loose wire. i just need to find time to look at everything tomorrow i hope. its really annoying.

 

could be as simple as your thermostat ground being a lil loose? give that a shot.

 

yeah it could be, it never does it under 4k, but tonight when i would cruise at 4500 in like 3rd to get it to do it, it was doing it a good bit, jumping from 4500 to 6 and sometimes it was getting an 8k signal cause my shift light would kick slightly in my face but i dont think the oem tach could keep up with that. whats causing that is all the wires are fine?

 

spoolinmatt's right. It's either the CKP sensor inside the distributor or it could be the thick blue wire comin out of your distributor into a 2 pin plug (the other wire is black/yellow I believe, which should be 12V). Make sure this wire isn't grounding out anywhere or has a break in it. Any small break in this wire will cause your tach to jump like crazy.

 

sorry,... I meant dirtysol was right. not spoolinmatt. Anyway, try replacing your distributor with a friend as well and see if that works. If it does, the problem should be inside the dizzy.

 

ill check all the wires, is the ckp sensor changeable inside the dizzy. i cant just trade with someone because there isnt anyone in my town that has an obd1 b16/b18c lol. they are either obd2 or obd0

 

apparently i don't know what im talkin about,not like i've had this happen or anything.but go ahead and replace the dist. or the cps.
good luck.

 

this is spoolin matt

are you being sarcastic or did it really happen to you before. im just trying to figure this out. i can change the ignitor easily, just gotta get with my friend on it. heres something to add. if the ckp or the ignitor were giving out bad signals, wouldnt the ecu see that as well, and engage vtec if my tachs read like 5500 and im really at 4500, cause my vtec hits at the exact same point everytime regardless of what my tach says.

 

yeah iwas being sarcastic,i'm a tech. at honda and have seen this a few times.and replaced the ignitor and cured the prob. but it may be something different.id say try changing it if your friend has one to swap it with.post up and let me know what happened.

 

ok so today i was driving and my tachs were really going at it, and then my factory tach STOP working, but the digital tach keeps right on trucking and it was reading properly. could the oem tach be shorting and making the digital one expletive up with it. this seems like tach failure or wire issues, again i havnt had time to address wiring issues, but with that instant happening, it seems as though it ruled out the distributor.

 

loose wire behind your cluster..

 

i forgot to add that on rare occasion, the digital tach will stop working completly and the factory tach will keep trucking, but i think it still acts gooofy. LOL!!!!