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Discussion Starter · #1 ·
Hello,

Can anyone confirm whether the 2.5 24V in 156 uses a 60-2 trigger wheel on the crankshaft position? What is the trigger wheel on camshaft position?
Also, can anyone provide the stock injector size? Mine uses stock yellow big short EV1 Bosch units?

I am planning a standalone ECU for a winter project maybe.

Best regards,

Stjepan
 

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It looks like the crank position sensor is indeed 60-2. It's mounted on the bottom of the oil pan pointing towards the flywheel, and there's a 60-2 trigger wheel on the flywheel.
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The cam sensor is a simple hall effect sensor on the back the exhaust cam on the front head, looks to be one pulse per revolution. I've also seen some pictures of the trigger on the cam wheel (don't know which engine has which, Alfa workshop manuals are a bit of a mess...), but it works exactly the same.
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Yellow EV1 injectors are 190cc/min.
 

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Discussion Starter · #3 ·
That is awesome information! Thank you very much!

Is the CKP sensor also Hall effect or is it a VR sensor?

This seems like it is not too much trouble to make it work with a standalone ECU. Only other concern now is how will the knock sensors work with standalone ECU...
 

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The crank sensor should be a VR sensor. VR sensors are usually 2 pin and hall are usually 3 pin, but here the VR sensor is 3 pin. The 3rd pin is just the shield however as you can see in the picture.
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The stock knock sensors are most likely tuned to a specific frequency, which will only detect knock at a specific frequency. On a stock engine the frequency of potential knocking should be the same but it's not the very best. You can swap them out and use "wideband" knock sensors that can pick up a wider frequency range, and a good standalone ECU that can properly do knock control. I have my knock sensors disconnected and running Megasquirt 2 on my GTV TB. It's really basic, but it works. The timing is really conservative anyways so I really don't think knock will occur. Tuners often like to use external knock detection equipment for tuning the ignition anyways, though I guess this is less critical for your part if you plan to run your 2.5 naturally aspirated.
 

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Discussion Starter · #5 ·
Seems like it is a VR sensor. Great info.

Yes, I considered widebands because I plan to eventually use forced induction.

My plan is to use the Ecumaster EMU Black.
 

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Discussion Starter · #6 ·
The crank sensor should be a VR sensor. VR sensors are usually 2 pin and hall are usually 3 pin, but here the VR sensor is 3 pin. The 3rd pin is just the shield however as you can see in the picture.
View attachment 954189
View attachment 954190
The stock knock sensors are most likely tuned to a specific frequency, which will only detect knock at a specific frequency. On a stock engine the frequency of potential knocking should be the same but it's not the very best. You can swap them out and use "wideband" knock sensors that can pick up a wider frequency range, and a good standalone ECU that can properly do knock control. I have my knock sensors disconnected and running Megasquirt 2 on my GTV TB. It's really basic, but it works. The timing is really conservative anyways so I really don't think knock will occur. Tuners often like to use external knock detection equipment for tuning the ignition anyways, though I guess this is less critical for your part if you plan to run your 2.5 naturally aspirated.
Where are you getting these diagrams from? Can you send me those?
 

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They are from the GTV workshop manual. In the section for the 3.0 v6 there should be "some" similarities to the 156 2.5... You can also download the 156 eLearn, should be okay to find if you google for it.
 

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Discussion Starter · #8 ·
They are from the GTV workshop manual. In the section for the 3.0 v6 there should be "some" similarities to the 156 2.5... You can also download the 156 eLearn, should be okay to find if you google for it.
I thought you maybe had some sort of factory wiring diagrams of factory manual. It is a shame that we not have access to factory information like on AllData etc. Which would describe theory in operation of certain systems, code setting criteria...
 

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The injectors are 224cc
 

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This is what I found last time, someone asked for it (not very long ago). I wouldn't think there's 190cc injectors in the V6, but I may be wrong.
 

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Discussion Starter · #12 ·

This is what I found last time, someone asked for it (not very long ago). I wouldn't think there's 190cc injectors in the V6, but I may be wrong.
This is a another topic where they are claimed to be 190cc:

 
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