mortificationrock

Ok I was wondering if anyone knows what causes a bad tach reading. I mean my tach needle is a little wigglely while I accelerate. I also noticed that one wire from the dizzy is kind of ripped. I believe it was a brown wire. Does anyone know what that wires purpose is? Ground, signal etc?

z6hatchboy

i may get in my service manual later and look up that wire. If you have a multi-meter or a test light you can get a idea of what that wire is. If that wire isnt affecting it (it proabably is thought) the sensor for the tach is in the distributor. Borrow a friends dizzy that works good and see what that does

mortificationrock

oh yeah, I forgot this is on my 96 civic with a GSR swap. On the dizzy side not car harness.

supraccordlx

Do you have a chipped ECU? conversion harness? little more info please.

mortificationrock

No, stock ex civic EJ8 with a OBD 2 Gsr engine all stock. No chipped ecu.

Jimmy

iTrader: (5)

Jumpy tach could be signs of a failing ICM (ignition control module AKA ignitor) located inside your distributor..

You can pull the cap off and inspect the connections, but it could just be time for it to take a **** on you.. usually how it goes..

my tach started jumping around.. 20 seconds later.. car died.. no start, no spark.. bad ICM.

Also check the blue wire in the distributor plugs.. i believe is the tach signal wire..

mortificationrock

Well this POS has done it since day 1. And i have driven it like that for days and gladly it hasnt taken a **** on me yet. I was hoping it could have been that BROWN wire i was talking about. Cuz its sort of ripped. And its a pain to drive and one getting inaccurate tach readings not knowing what rpm your really at.

Jimmy

iTrader: (5)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mortificationrock &raquo;</TD></TR><TR><TD CLASS="quote">Well this POS has done it since day 1. And i have driven it like that for days and gladly it hasnt taken a **** on me yet. I was hoping it could have been that BROWN wire i was talking about. Cuz its sort of ripped. And its a pain to drive and one getting inaccurate tach readings not knowing what rpm your really at. </TD></TR></TABLE>

Not sure about the brown wire, reguardless.. patch it up with some good 3m super+ electrical tape.. or some cheap stuff

mortificationrock

I did. But i noticed its a little more peppy. thats it. But tach is still little jumpy. My main concern is actually KNOWING what that wire is. if ground, power etc. I dont have a wiring diagram.

mortificationrock

BUMP

Former User

The tach signal comes from the blue wire connected to the ICM in the distributor, if that is what you are asking.

Hook up an OBDII scan tool that also reads engine rpm. If the signal also jumps around on the scan tool, then the tach is fine and the problem is likely due to a bad ICM or a loose/damaged blue tach wire.


Modified by RonJ@HT at 3:59 PM 10/14/2008

94EG8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mortificationrock &raquo;</TD></TR><TR><TD CLASS="quote">I also noticed that one wire from the dizzy is kind of ripped. I believe it was a brown wire.</TD></TR></TABLE>

Check the color again. No wire coming from the distributor is brown. Might be dirty though and look brown.

mortificationrock

OK maybe tan. ill go look at it again but im sure it wasnt yellow though.

mortificationrock

TTT

Jimmy

iTrader: (5)

Why you bumping the thread.. I think everyone has done the best they can to help you without pics and with the information you've provided..


Did you test the ICM?

Did you check your wiring..