CA18DET factory ECU

Discuss topics related to the CA18DE and CA18DET series engines.
juss
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Joined: Tue Nov 01, 2016 7:25 am
Car: VAZ 2101+ca18det

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Hello.


I have weird problem with my CA18DET factory ECU, My engine came from factory with automatic gearbox but now I have manual gearbox and engine Ecu for manual gearbox. But I have tryed 3 different ECUs but all of them have weard problems.
All ECUs are 2371 39FF00
Ecu one: when RPMs are troping they are stopping on idle for a second, then dropping to 500 and up to ide again.
Ecu two: Same as ecu one but do not rise idle RPMs from 850, disconnect aac and reconnect, worked as ecu one.
Ecu three: worked fine until I tested spark plugs and now when I turn off the ignition switch nothing is happening, until I unplug ECU relay. I think I burned something in ecu.
I have deleted all things what can mess up idling except aac valve. I have cleaned and replaced aac valve many times.
It helps I can make video from 3 different ecu...

My question: Why is those CA18DET factory ecus so problematic when dropind to idling? Is there some components what are failind becaus they are quite old?


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louiswun
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Joined: Sun Jan 27, 2008 5:33 am

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If all ecu are 23710-39F00 , its an MT ecu.
It is not those CA18DET factory ecus problematic, its usually bad wiring or sensor.
If all idle control device working, idle will drop smoothly.
Idle contrl device included : air regulator, proper adjusted throttle body with coolant flow thru, TPS sensor, AAC valve, proper parts no. AFM.
Is there any device on your CA missing ?

juss
Posts: 13
Joined: Tue Nov 01, 2016 7:25 am
Car: VAZ 2101+ca18det

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I tested all components from ECU socket, all readings except AFM was fine.
Air flow meter is reading little bit off:
Idle is 1.6V (ok)
2500 RPM is 1.9v
3400 RPM is 2.2V
Manual is saying that on 2500 RPM should be 2.2v
I have 90 degree elbow between turbo and MAF. I mounted honeycomb in front of MAF but no change.

I tested A/T engine ECU, no problem when engine is going to idle.
With M/T ECU bigger the boost bigger the problem!

I have tested all components many times as service manual are saying and set idling, replaced AAC valve, clean all connections.
I have no idea what to to/test next :poke:

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louiswun
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Shoot a photo of your afm/ suction pipe/ turbo intake set up

juss
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Car: VAZ 2101+ca18det

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Here are some pictures, I hope they are helpful.

Image

Image

Image


I made 2 videos:
Multimeter are showing MAF voltage, Middle red gauge is A/F ratio, bottom left is intake manifold pressure.


Multimeter are showing AAC solenoid voltage.



I notice odd voltage drop in MAF video, but it can be badly connected multimeter leads what disconnect due to vibration.

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louiswun
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I think the air flow meter is to close to the compressor, it is better to place it right after the aire box, just like factory location.

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louiswun
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If the AFM place that clost to the compressor without 2 90 degree bends, it will causing too much reversion and swirl, both will affect AFM senstive to drop down to idle.

juss
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Joined: Tue Nov 01, 2016 7:25 am
Car: VAZ 2101+ca18det

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Problem solved!!! :woot:
Thank you louiswun!


It's interesting that I remember from other forums that between turbo and MAF there have to be at least one 90 degree bend that they aren't "seeing" each other.

What pipe size is better between turbo and MAF 60mm (factory pipe) or 80mm (between MAF and air box in my car)?

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louiswun
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Before the MAF (between the air box , pipe ID or air filter adaptor ID), it has to be 100% same size as the MAF inlet ID , you won't get correct readings if ID of the air box/air filter is not matching with the MAF.
After the MAF, use whatever you like.
One of my friend's S15, using a mushroom filter with a aluminium adapter which is 2 to 3 mm smaller than the MAF inlet ID, it read less air to the ecu and will have leaner AFR.

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louiswun
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NISSAN factory air box have a velocity stack built in the box, which works very well for the MAF, it has exactlly same ID as the MAF inlet.
If you place your MAF right after the filter box like nissan factory does, sure it will work better than close to the turbo inlet .

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louiswun
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Here is what I do , at least 2 90 degree bends between turbo and MAF
Screenshot_20200517-230548_WhatsApp.jpg

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louiswun
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Another sample
Attachments
Screenshot_20200517-231250_WhatsApp.jpg
Screenshot_20200517-231239_WhatsApp.jpg
Screenshot_20200517-231204_WhatsApp.jpg
Screenshot_20200517-231258_WhatsApp.jpg

juss
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Joined: Tue Nov 01, 2016 7:25 am
Car: VAZ 2101+ca18det

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Thank you again louiswun!

This is how I placed MAF, not the best solution but it should work.
Image
Image
Image
Image

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louiswun
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it looks ok to me

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float_6969
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Glad you guys got this figured out!

juss
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Joined: Tue Nov 01, 2016 7:25 am
Car: VAZ 2101+ca18det

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Hello again!

when I'm slowly rising engine RPMs under vacuum to 4500, engine starts to leaning 1:20. When i'm rising revs higher, A/F ratio is going back to normal.

This problem was when MAF was in old location, I thought it disabeart along idling problem, but now I notice it again.

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louiswun
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Stock injectors and FPR ?

juss
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Yes stock injectors and FPR.

Upgreats:
044 fuel pump (replica), GT2860R turbo.
Fuel pressure is slightly higher than with stock pump, but otherwise everything worked.


I have ordered Nistune but delivery is delaying.

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louiswun
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juss wrote:
Sat Jul 18, 2020 12:00 pm
Hello again!

when I'm slowly rising engine RPMs under vacuum to 4500, engine starts to leaning 1:20. When i'm rising revs higher, A/F ratio is going back to normal.

This problem was when MAF was in old location, I thought it disabeart along idling problem, but now I notice it again.
It might be the ECU switching from sequential to batch injection, there is a lean spot at that moment, but I didn't know even if it happen on stock injectors.

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louiswun
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it is better to use JDM S14 Zenki ecu (if you had not order CA18 nistune), only swap few pins to use, much better response and better throttle enrichment (CA18 ecu can't tune the throttle enrichment, its alpha N but no real effect)

juss
Posts: 13
Joined: Tue Nov 01, 2016 7:25 am
Car: VAZ 2101+ca18det

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Yeah I ordered CA18 Nistune with license.
I think there are way to cancel my order (like 80% of refund or something) Or try to sell it locally after it has arrived.


Is there easy way to make sore it is JDM S14 Zenki ecu?
23710 69F00?

Comparing CA18 and SR20 ECU pinouts, they are really different for me...

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louiswun
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yes, 69F00 , to use it on CA , it is around 6 wire to pin swap, not difficult (if you know what pin goes where )

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louiswun
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And use the VTC pin to activate the 8 port butterfly, it works and I've done it.

juss
Posts: 13
Joined: Tue Nov 01, 2016 7:25 am
Car: VAZ 2101+ca18det

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Comparing schematics on my last post I have to swap pins:

3 -> 11 (Ignition 3)
6 -> 9 (A/C Relay)
5 -> 25 (Boost solenois)
8 -> 113 (Butterfly)
11-> 12 (Ignition 4)
106->4 (Idle Air Contro Valve)
54 and 57 empty

Do I understand right that SR20 don't use throttle switch? So pin 54 and 57 are not used.

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louiswun
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juss wrote:
Mon Jul 20, 2020 12:04 pm
Do I understand right that SR20 don't use throttle switch? So pin 54 and 57 are not used.
SR do not use throttle switch (Idle switch), but function are built in to the ecu, TPS voltages are "memory" and needs to reset if TPS voltage vs Throttle posistion has been changed .
ie : TPS sensor location and the throttle plate relation had been changed (fully closed posistion)

juss
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Joined: Tue Nov 01, 2016 7:25 am
Car: VAZ 2101+ca18det

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I was trying to find ECU from local market but it is quite tricky, they aren't many here.
I'm hoping to find some good deal on web but if there is good price then shipping is expensive and visa versa.

If I find good deal I will try 69F00 ECU.


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