Honda Civic 91 Hatchback Si-RPM

[Gito]

Removed, repaired and reinstalled my pedal assembly then I replaced the distributor cap and rotor on my 91 Honda Civic Hatchback Si. I started my car and I immediately noticed that the RPM needle does NOT work.

Took my car for a drive and it ran smooth.
I didn't dare go on the freeway for fear of getting stranded. My triple A (AAA) card already has been used 4 times (4 tows) for the year.

Observations:

I noticed a small cut ( disconnected) wire next to the other disconnected wire that goes to a thermo switch that activates the temp gauge. I looked around to see where the small wire hooks up to but I could not find anything.

Something must be there and I will go ahead and look some more tomorrow.

Could this wire, located under the distributor, be the one causing the problem.

I have 2 other distributors that I will be swapping to see if the RPM needles comes back and moves.

Please advise

 

[CHARLIEBRONSON21]

Mine was a shorted wire in the back of the gauge cluster. (93 civic) but I would just retrace what you did and see if something got punched off.

 

[Olas]

The tacho is driven by the pulsed earth signal from the coil - dizzy shouldn't make any difference.

Get the multimeter out and start probing to find the fault. I'll bet you a doughnut it's a continuity problem

 

[Tegger]

Originally Posted By: Gito
I noticed a small cut ( disconnected) wire next to the other disconnected wire that goes to a thermo switch that activates the temp gauge.

Is that wire BLUE? If so, then that's the tach-signal wire.

The tach is driven by the igniter (ICM), not the coil. A pulse is sent down the blue wire at each ignition event. Absent that signal, the tach will not function.

 

[Gito]

The disconnected wire appears to have an off orange brownish color.

But I did notice that a small blue wire is sort of crimped and exposed.

I will wiggle around the wires to see if the blue wire is split.

I was handling the distributor while it was still connected.
Usually I disconnect the distributor and remove from the shaft

I might have twisted the blue wire

Still wondering about the other wire...

 

[Tegger]

Originally Posted By: Gito
The disconnected wire appears to have an off orange brownish color.

Is it a solid color, or does it also have a stripe of another color?

Also, is the wire part of a distributor connector? The engine harness? Other?

Clean a spot on the wire with some spit and see if the color gets clearer.

 

[Gito]

Got to the fuse box and removed and reinstalled the same 10 amp fuse (dash lights) that was NOT burned out.

I previously had not noticed that the dash lights were not working so the info that I provided to the forum was incomplete, my mistake.

Again, the fuse appeared not to be burned out.

Now for the wire, I cleaned it up and it is a solid color without a stripe.

I looked and looked and looked and then BAM, I saw that the Oxygen Sensor (O2) connector tucked under the radiator.

I had my clutch replaced (under warranty) a few months ago and these guys must have snapped the wire and decided to just tuck it away out of sight. What they didn't know was that the check engine light kept coming on and off for the next few months.

Well that explains my check engine light issue.

Pretty sure that the cut off wire to the O2 sensor is whats causing my Engine light to turn on and off.

Now that bad thing is that the end that broke off is right at the connector end to the wire harness and there is no way that I can solder that wire back to the connector belonging to the O2 sensor.

Please advise

 

[Gito]

Update:

OK, so I removed a small grommet that is inserted on the end of the connector.

I then proceeded to cut off a small piece of the end of the connector (circular cut, similar to cutting a PVC pipe).

This would then allow me to connect with a longer wire and solder both wires together.

Hope it works