Vtec don't engage with low IAT

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

Post by contectr » Wed Feb 13, 2013 6:14 am

Nazul, the fact is on 5 cars..
2 cars are oem Honda Ep3 with stock engine Harness and bolt on mods
1 car is my street track day oem Honda Ep3 with twinscroll turbo kit
2 cars is a Lotus Exige-Elise with engine swapped K20A and K20A2 with stock Honda engine Harness and swap elettrical harness conversion listed on tech Hondata website (engine swap).
I repeat them today on my car, if i start the car and the IAT are below than 5-6° , a little drive for warmup the car the vtec don't engage. At this time, i shutoff the engine and restart immediatly and they work!
Honda Ep3 stock k20a2 jrsc

Nazul
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Re: Vtec don't engage with low IAT

Post by Nazul » Wed Feb 13, 2013 6:18 am

And how long is your warmup drive

contectr
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Re: Vtec don't engage with low IAT

Post by contectr » Wed Feb 13, 2013 10:58 am

Nazul, my warmup drive is about 12 km...after this the ECT are at 82°C...i think it's ok for the vtec operation!
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 » Wed Feb 13, 2013 5:07 pm

Do all of these vehicles use the PRB calibration, or are some PRA calibrations?
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contectr
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Re: Vtec don't engage with low IAT

Post by contectr » Thu Feb 14, 2013 6:37 am

Hondata, the 2 Lotus swapped car use a PRB ecu and PRB calibration..
The 3 EUDM Ep3 Honda with K20A2 use a PRA ecu and PRA calibration..

Do you need the PRA calibration?
Honda Ep3 stock k20a2 jrsc

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Re: Vtec don't engage with low IAT

Post by Hondata » Thu Feb 14, 2013 11:23 am

The PRA calibration would be nice so that I can test that as well.

This is an odd problem - we have not had any other reports of this problem, yet you have 5 different cars with the same problem using two different types of calibration. In the ECU code it looks for minimum speed, minimum ECT & certain error codes cannot be set (MAP sensor, VSS, VTEC, VTC & cam/crank sensor error codes). Then it looks for an after-start delay of 10 seconds and the VTEC window, and there's not much else.

Try the beta release here: http://www.hondata.com/forum/viewtopic. ... 380#p64380
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contectr
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Re: Vtec don't engage with low IAT

Post by contectr » Thu Feb 14, 2013 4:22 pm

Hondata,
- For minimun speed i don't think because i tested them on my car with 3rd gear engaged..
- My Vss speed sensor work great
- I don't have any issue of camshaft allignement or cam sensor error..

I attach the calibration PRA NA engine, in this car Kpro II.
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Honda Ep3 stock k20a2 jrsc

contectr
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Re: Vtec don't engage with low IAT

Post by contectr » Fri Feb 15, 2013 7:47 am

I have the serial number of 2 ecu:

- Ep3 Turbo kit 37820-PRA-E12 149176-3Y10
- EP3 NA 37820-PRA-E13 463774-5317
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 » Fri Feb 15, 2013 9:30 am

Once I had the PRA calibration I was able to find the problem almost straight away. Your maximum MAP for closed loop (currently 10 kPa) needs to be higher than the lowest that the MAP sensor will read. It appears that the ECU only updates its internal temperature reading for VTEC when not under full load, and the 10 kPa setting was making the ECU think it was at full load all the time. Now when I look at the PRB calibration, it has the same value too.

I will change the ECU code so that it does not do this in the future, but the quick fix is to increase the maximum MAP for closed loop.
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Re: Vtec don't engage with low IAT

Post by Nazul » Fri Feb 15, 2013 9:58 am

Whats the purpose of setting this to 10 anyway?

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Re: Vtec don't engage with low IAT

Post by contectr » Sun Feb 17, 2013 6:30 am

Ok hondata..i have set this value at 10 kpa because the car is without lambda sensor and go on open loop always!
If i set at 20 kpa this can solve the problem?!?
Honda Ep3 stock k20a2 jrsc

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Re: Vtec don't engage with low IAT

Post by Hondata » Sun Feb 17, 2013 6:52 pm

Hondata

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Re: Vtec don't engage with low IAT

Post by peterjzocco » Thu Aug 21, 2014 5:51 pm

Hondata, I have a I/H/E and kpro...my vtec is set at 3800, about a week after the kpro install my ECL came on with daughter board communication error(low voltage when cranking). When driving the vtec had trouble engaging and the car would jump when vtec tried to turnover. Also, my idle was extremely unstable. I turned the car on and off, ECL went away. I took the negative terminal off to reset the code on my kmanger...but now my VTEC won't engage, and if it does it's completely at random. Is there a known solution to this problem?

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Re: Vtec don't engage with low IAT

Post by Hondata » Thu Aug 21, 2014 7:05 pm

Your problem is not related to the original problem in this thread.

Daughter board communication error is normally ossociated with a bad battery of the battery being relocated. Follow the posting guidelines and provide more information (in a new thread).
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