I'm sure someone has run into this before.

Still haven't changed the cluster in my 00 LS, but I just put in a 96 spec JDM ITR.

All is well other than the tach which is quite erratic. Essentially, once I hit above 6500 rpm, it bounces all over the place. I expected it to be off until I put in the ITR cluster, but not bouncing all over like that.

 

No.

Change your distributor soon, before it dies.

 

The ITR motor was in my EK up till last week. I had an CTR cluster in the EK, and no problem whatsoever. I doubt the distributor crapped out instantly like this.

I was more thinking, the JDM ECU outputs a voltage outside the LS tach range.

thanks for the reply

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Frog &raquo;</TD></TR><TR><TD CLASS="quote">
I was more thinking, the JDM ECU outputs a voltage outside the LS tach range.
</TD></TR></TABLE>

No. Your cluster picks up the tach reading for the distributor.

Check your ECU plugs, check your cluster plugs, check your distributor plug, make sure they are secure.

If not, your distributor ignitor is going out most likely.

 

The Obd2b clusters gets the signal from the ECU, not from the distributor. I'm fairly certain the ECU outputs to the cluster the ignition signal or the signal it receives from the CKF. Either way, the RPM signal does not come from the distributor on 00-01 Integra.

The tach signal right now is a tap from the ignition output signal at the ECU. I'll run the signal from the OBD2a distributor directly to the Tach and see if that's the only solution.

 

they all get their signal from the ecu....

but the reason your tach is acting all funky has nothing to do with your ecu or cluster, its in the wiring somewhere or like the above guy stated
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by neo_ &raquo;</TD></TR><TR><TD CLASS="quote">

If not, your distributor ignitor is going out most likely. </TD></TR></TABLE>

 

Well, believe what you will, but the signal at the tach does not come from the ECU on all Hondas.

Not to try and argue, but here's a quote from the Honda ETM, just so we don't put out misinformation:

Integra 98-98 Model: "The tachometer drive circuit receives pulses from the ignition control module in the distributor assembly. The solid-state tachometer then displays these pulses as engine speed."

Integra 00-01 Models: " The tachometer drive circuit receives pulses from the PCM or ECM. the solid-state tachometer then displays each pulses as engine speed."

The circuit diagram supports the text above.

The nature of my question is whether anyone knows the voltage range of the signal received from ICM and the ECM.

 

No further comments from me.

 

I'll try a couple of things and post what I come up with. Even if it is the ignitor.

 

Just in case anyone else runs into this. The tach signal is not accurate coming from the ignition signal at the ECU and needs to be wired from the distributor. This only applies to JDM ECUs I believe. It seems that USDM ECUs derive the tach signal from the CKF sensor, which is non-existent on JDM ECUs, at least not on OBD2a. The distributor is wired for tach signal, but in most USDM OBD2b cars, the signal stops at the plug and does not continue through the chassis harness.

In this case the distributor worked just fine. The tach signal would simply jump around above 6000 rpm when taping in the ignition signal output from the ECU .

Having said all this, I don't recall anyone running into this problem with OBD2b Civic or JDM clusters, but that may just be the luck of the draw.

 

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