CPR Tach light goes off and car shuts down

Hondata CPR (Coil Pack Retrofit) support
white2015
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Joined: Thu Jul 16, 2020 11:23 am

CPR Tach light goes off and car shuts down

Post by white2015 »

Hello All,

New to this group, any help is greatly appreciated!

I have had my CPR kit on my boosted b18C for years now. The car has been tuned multiple times and has always done well. I finally took the car for a long drive (About an hour each way) and on the way back i had an issue that I cant track down.

The gauge cluster tach drops to zero and the car wont rev. I looked down adn the ignition light on the CPR box was off. Once it came back on i had a tach again and the car ran fine. However, it continued to randomly do this and i could barely get it home. It would constantly shut off and sometimes not start. I looked at the wiring and cant find an issue, and now i cant get the problem to occur while it is idle. Any thoughts on where i should be looking?

Thanks for the help!
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Spunkster
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Re: CPR Tach light goes off and car shuts down

Post by Spunkster »

Since this is an intermittent issue, it is more than likely a wiring related issue. IT could be a bad connection bad solder joint on joined wires, or an internally broken wire from fatigue.
white2015
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Joined: Thu Jul 16, 2020 11:23 am

Re: CPR Tach light goes off and car shuts down

Post by white2015 »

Yeah, i definately felt like it was going to be but i couldnt find anything. I am confused on the ignition light. Doesnt the cpr provide a tach signal for the gauge cluster tach? I had a solid sync light, so what wire would turn off the output of that tach light? If i am understanding it right? Thanks for your reply!
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Spunkster
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Re: CPR Tach light goes off and car shuts down

Post by Spunkster »

Follow the steps in the help file for troubleshooting: http://www.hondata.com/help/cpr/troubleshooting.htm
white2015
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Re: CPR Tach light goes off and car shuts down

Post by white2015 »

Yes, i tried their troubleshooting guides. I even checked when it wasnt working and the wire was there and had a solid connection. I tried moving it around and it would have no affect either way.
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Spunkster
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Re: CPR Tach light goes off and car shuts down

Post by Spunkster »

How are the wires joined?
white2015
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Re: CPR Tach light goes off and car shuts down

Post by white2015 »

I have a wire-worx harness and it was setup for cpr kit from the beginning, so everything is pinned in the harness. Nothing is t-tapped or soldered that i can see.I tried gently pulling on the pins to see if any of them were loose, but they all seemed normal.
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Spunkster
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Re: CPR Tach light goes off and car shuts down

Post by Spunkster »

It could be an issue with the wireworx harness. We have seen issues with them in the past.
white2015
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Re: CPR Tach light goes off and car shuts down

Post by white2015 »

Yeah, nobody seems to like any aftermarket harness. I keep looking at it and cant see anything though. If it happens again is there anything i could look for in a data log that may help explain anything?
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Spunkster
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Re: CPR Tach light goes off and car shuts down

Post by Spunkster »

IF it is loosing the signal it is most likely an issue with wiring, unless it is the ECU that is loosing power.
white2015
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Re: CPR Tach light goes off and car shuts down

Post by white2015 »

IS the Tach light a signal in or a signal out? I thought it was an output from the cpr to the gauge cluster, but wasnt sure.
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Spunkster
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Re: CPR Tach light goes off and car shuts down

Post by Spunkster »

You are saying the Tach light, but there is no tach light on the CPR. If you mean the ignition light, that is the signal from the ECU to the CPR.
white2015
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Re: CPR Tach light goes off and car shuts down

Post by white2015 »

Yes, sorry that is what i meant. If it is a signal from the ecu, maybe something in the tune was giving it an issue. Thanks for the help!
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Spunkster
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Re: CPR Tach light goes off and car shuts down

Post by Spunkster »

The ECU cannot make changes to itself. If this is intermittent, then it is most likely wiring related.
white2015
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Re: CPR Tach light goes off and car shuts down

Post by white2015 »

Hello again. I have been going through the wiring and cant find a single issue. I even went as far as unhooking the ecu and laying it on the floor, with hopes that i could move it around and cause the problem to happen if was something loose. It never happened. I let the car sit idling for over 45 minutes and the problem wont occur. I wiggled and moved every wire i could think of and even rechecked the wiring at the distributor.

Whats interesting is that within 10-15 minutes of driving it always occurs and then gets worse. It gets to the point to where the car shuts off and wont restart. Then once I i get the car started i get it back into the garage. This time the car wouldnt start for like 2 minutes, and i drained the battery, and had to jump it. Then i let it sit idling in the garage again and it wouldnt shut off.

However, the good news is that i got a datalog of it happening this time. I dont know exactly what to look for in the datalog but I noticed that it shows a boost cut, rev limit, and an ignition cut all at the same time when it happens. It also throws up a CEL but it doesnt store any codes. Does anyone else have any ideas? Does this point to anything? I am just driving slowly, not boosting or going high into the RPMs.

Datalog is attached, thanks for any help!?
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