Firstly, I know there have been several posts on this topic from years ago but i haven't found one yet with an actual resolution. Im really hoping to get this fixed as soon as possible.

Anybody have any idea why the RPMs have stopped working after installing a new distributor? The plugs match and connect blue wire to blue wire (rpm signal). Everything was working fine before the previous dizzy stopped working.

Tried 2 different brand new dizzys, still no rpms. Also took a multimeter to the blue wires and they are getting signal.

Motor: 98+ spec B18CR (JDM)
Chassis: 99 EJ6 (EK)
Gauges: S2000 ap1 cluster w/ speedo healer

 

The stock 99 Civic gets the rpm signal from the ECU, not the distributor ICM. This likely is the cause of your frustration.

 

What was wrong with your original distributor ?

 

Thanks for the response! So what about changing the distributer to a new one would cause this to stop working when it was fine before?

 

Screw came loose from the rotor and thrashed around inside, causing it to stop working. Car died mid drive..

 

Is your 99 Civic running an OBD2b ECU and distributor? Or is it running an OBD1 ECU?

Does the replacement distributor exactly match the original?

 

Replacement dizzy is an oe replacement for a 98 b18cr which is what was originally on the motor when installed BUT, it's an after market unit.

Not completely sure on the ECU (fairly certain it's obd2a)..i'll confirm and get back with that info.

Again, thanks for your help!

 

Aftermarket distributors for our Hondas can be unreliable. How and where did you verify an rpm signal from the distributor blue wire?

The stock 99-00 Civics had an OB2b ECU. Did the 98 Integra have an OBD2a or OBD2b ECU?

 

Verified w a multimeter from the harness plug that was connected to the dizzy plug that signal was coming through. Also tried jumping the wire from the dizzy side to the blue wire near the firewall at top right of the engine bay with no success.

96-98 b18 is obd2a i believe, so im only assuming that its obd2a based on that. I will confirm tomorrow to back that assumption up.

 

So after talking to the guy who did my swap, sounds like the car is still wired as it was stock but is using an ecu adapter for the ECU from obd2b to obd2a. He said that the harness doesn't even have the blue wire at all and that the car gets the signal from a Yellow and Green wire from the distributor and that does the same thing as the blue wire. I still don't understand how changing the dizzy could cause this to stop working if nothing else has changed. The wiring and connections should still be the same..

I'm going to try to jump from the Yellow and Green wire to the blue wire at the firewall when I get home from work and hopefully something good happens.

 

This^ seems like a risky location to obtain the rpm signal because the Yel/Grn wire sends the ECU spark signal to the distributor ICM. Ask the previous owner why he did not instead use the blue rpm wire from the distributor ICM for the tach signal. Connecting the blue distributor wire to the tachometer would be the best way to go.

 

Actually, the car does have a stock blue rpm wire but it runs from an ECU connector to the cluster. I suspect that the previous owner tapped into this blue wire to get the rpm signal to the S2000 cluster. Alternatively, he ran an entirely new wire from the distributor to the S2000 cluster through the firewall.

 

He is saying that there is no blue wire in the engine harness because its a 99. I think my issue is that the car is still using a 99 harness (obd2b) with a 98 dizzy (obd2a) like you originally stated. I have tried jumping the blue dizzy wire directly to the light blue wire on the shock tower and still got no results. He is telling me that the yellow and green wire sends the rpm signal from the igniter, this is why I thought I might try jumping it. This whole thing is driving me nuts, haha.

btw, this guy never owned the car, he is just the person that did the swap.

 

He also said the wire splits somewhere along the way in the engine harness and runs off to connect to the shock tower or cluster. So this might be what you are referring to..

I also saw that the original dizzy was stamped TD-87U and the new one is TD-84U. Do these differ by obd2a or obd2b in anyway?

 

He is wrong (i.e., tachometer test connector).

Post pictures.

The guy doesn't understand how the ignition system circuit works. The ECU sends the spark signal to the ICM on the Yel/Grn. Splicing into the Yel/Grn wire seems risky and unnecessary.

My recommended fix --> Run a new wire from the distributor blue tach wire through the firewall to the cluster.

 

Post pics that allow comparisons of the connectors and wire colors.

 

Light blue wire at shock tower i jumped to.

New TD-84u dizzy connector.

Old TD-87u connector.

New dizzy wires.

Old dizzy wires

 

First pic:

If the blue wire in this pic is attached to a nearby 2P connector (tachometer test connector), then it should have continuity with the blue wire attached to the cluster tachometer. If so, this means you should be able to get the cluster tach working again by running a new wire from the blue distributor wire to the blue wire attached to the tachometer test connector.

 

I guess my next step is to test the light blue wire near the shock tower...should have done that to begin with i suppose..yeesh

 

For both rpm signal and continuity with cluster blue wire.

 

Thanks again for the help, I'll report back once I figure out a bit more.

 

after further testing, multimeter is getting readings to the test plug and readings from the actual wire in C5 in back of the cluster but still showing no rpms on the cluster. Jumping from dizzy blue to tester also did nothing..im so lost. Could be the cluster is bad. Testing a different one as we speak

 

Oem cluster not getting RPM's either...could it be the ECU thats the problem?

 

Run a new wire from the test connector through the firewall to the cluster. The cluster tachometer should work if you do this.

 

are you in socal? How much beer to i need to buy you to get you over here lmao