Vtec don't engage with low IAT

K-Series Programmable ECU installation questions / support issues
contectr
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Vtec don't engage with low IAT

Post by contectr »

On my euro civic type R with Gt3582R turbo kit i have this issue.
With low winter climate (i live in north italy and the IAT at start up engine i near 0°C), at the first engine start the vtec don't engage.
But if i turn off the engine and start it again the vtec work normally!
I have the same issue with my customer and NA configuration.
It's the second winter with this problem.
I checked the voltage battery when i crank and it's 10.5 volts.
It's a internal Honda ecu protection?!
Honda Ep3 stock k20a2 jrsc
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Hondata
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Re: Vtec don't engage with low IAT

Post by Hondata »

VTEC does not operate with the coolant below 60 degrees C. Are you finding that it does not operate once the ECT reaches 60 degrees?
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Re: Vtec don't engage with low IAT

Post by contectr »

Hondata, the ect was at 82 celsius degree!
I have a PRA ECU on a Honda Civic Type R eudm!
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contectr
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Re: Vtec don't engage with low IAT

Post by contectr »

this is the datalog.
The vtec is set to 3300 rpm and they don't switch on.
After this i have turn off-on and start the car again...vtec work normally.
It's strange..
The engine is a K20A2 with forged internals.
In the customers car, same issue on NA K20A2 stock with only Kpro. The customers live on a very cold climate (mountain) with IAT at startup below the 0° celsius.
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Hondata
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Re: Vtec don't engage with low IAT

Post by Hondata »

Ok, we'll look into it.
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Re: Vtec don't engage with low IAT

Post by contectr »

Hondata, if i remeber right, the first time i have this isssue are about november 2011 with the Kmanager version 3.0.3.
The winter before this release i don't have any problem with the vtec and low climate temperature at startup..this can help ?!
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Nazul
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Re: Vtec don't engage with low IAT

Post by Nazul »

Did u update kmanager already and reuploaded the map?
contectr
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Re: Vtec don't engage with low IAT

Post by contectr »

Yes i have the kmanager v 3.1.6 on Windows 7. I have try with an erase ECU and upload the Kal. And the problem is not solved.
The kpro is a v2 and the my ECU is a 37820-PRA-E12
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Re: Vtec don't engage with low IAT

Post by contectr »

I Made few test and if at the cold start the iat is low than 5 degree celsius the vtec don't switch on!
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Re: Vtec don't engage with low IAT

Post by contectr »

Hondata, yesterday another customer call me for this same problem on a PRB ecu and Kpro III.
DO you solved this problem?
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Re: Vtec don't engage with low IAT

Post by contectr »

Hondata, today on a time attack race, two customers have this problem because the IAT at the startup are very cold (+1 °C).
This is embarrassed, one of the two clients being inexperienced drive for the entire race without realizing that Vtec don't engage :-(
This time is a PRB ecu + KPro III and kal uploaded with 3.1.6 Kmanager, swapped on a Lotus elise car with K20A and Rotrex supercharger
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Re: Vtec don't engage with low IAT

Post by Hondata »

We cannot reproduce the problem here. Can you follow the posting guidelines to help us?
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Re: Vtec don't engage with low IAT

Post by contectr »

Hondata, it's very easy..
First start of the day, if the IAT temperature are below than 6 °C, drive the car and when the engine is warmed the vtec don't engage. I shut off the engine, re-start them and the vtec work.
If at the first start of the day the IAT are over 6°C the vtec engage without any issue..
I attach a kal of PRB ecu with Kpro III that have this problem..
Now i have 5 cars with this problem with PRA o PRB ecu and Kpro III or Kpro II. One of this car is my Ep3 K20a with a twinscroll turbokit.
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Re: Vtec don't engage with low IAT

Post by Spunkster »

we are looking into this
Nazul
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Re: Vtec don't engage with low IAT

Post by Nazul »

I've ran in those temps multiple times without one interruption of VTEC, so I find it hard to believe its related to hondata.
Last months everyday is under -5 degrees celcius here in Belgium.
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