Newbie - Questions to get going in the proper direction

[snomo]

Hello,
Although I have been lurking in the forums, FB, and most recently discord, I just joined the forum today.

I have many years of automotive experience, and a fairly solid understanding of automotive electronics, wiring, mechanical experience, etc, I am by no means a sware developer. I can get around a computer in Windows, and Linux, but never had the training or experience to develop code.

A few years ago, my son got us into Megasquirt, and we converted his Volvo 740 (inline 4cyl, 2.3l, single cam, "redblock"). At that time, he also added a turbo. This was a pretty steep learning curve for me, but I was able to help him getting it all to work.

Now, I am interested in converting a 1994 Volvo 850, with a inline 2.5l "whiteblock" dual overhead cam's, NA. The original controls for this vehicle is a Bosch "Jettronic" LH3.2. There is a separate ECU for the ignition, and fuel injection. The fuel injectors are fired in a batch, and there is only one coil which is fired from a "ignition box". The coil distributes the spark with a rotor/cap.

As I have followed Rusefi for a while, I have many questions that I hope someone could help with, or at least point me in the proper direction:
1 - I am considering the uaEFI121 package with crimp kit. In the HW description, I see that:
a. it has 2 VR's, but I am unsure as to what is meant by VR-discrete vs MAX9924
b. Optional EGT. What is needed to add that, if I ever wanted to?
c. Optional on Board MAP. I would like this, but where do I find specs to order?

2. I believe the volvo flywheel is a 60-2 tooth pattern, with a VR sensor. The cam sensor is 50% duty cycle. The sensor is a hall. Any concerns?

3. I need 2 high current sinking outputs for the IAC, as well as 1 high current output for the batch Fuel injectors (sinking). I believe there are only 2 high current outputs on this board. So is there an easy way to get a 3rd?

4. I would also need a way to control the engine cooling fan (2 outputs for high/low speed), Fuel pump control, variable intake runner control (solenoid vacuum control), Air conditioning control, etc. Looking at the "pinout" page (https://rusefi.com/docs/pinouts/hellen/uaefi121/), it tells me what each pin is, but there are no current or frequency specs. Can I map any input/output to ANY function in sware? Is there somewhere that tells me what each pin is capable of (V or A)?

5. To support many of the Dash/AC systems, I would imagine I would have to use the "LUA" scripting. Is there a good guide to understand this scripting language?

6. Since the original control is done in 2 separate ecu's, I am trying to figure out a way to interface the Rusefi controls without hacking up the cars harness. I do have "spare" volvo ecu's, and am considering removing the factory connectors from the ecu's to make a "interface". A bit harder to do when there are 2 ecu's. This car is a manual, if it would have been an Auto, then there would have been 3 ecu's.

Finally, I attached a marked up schematic of the Volvo control system. If interested, take a look and I am open to ideas/suggestions.

Regards,
Mark

[AndreyB]

Documentation progress has happened https://github.com/rusefi/rusefi_documentation/commit/9bded6710a02de514084e891bd7e7dc4c4600d97

[snomo]

I guess I attached the wrong doc earlier. Here is the Volvo diagram....

[jc10000rpm]

Engine Cooling Fan control

the 2 speed fan relay found in the volvo's is great simple setup iv used before. (your car has one)
No need to get the ecu involved. You can get a dual temp fan switch (screw into head) from a bmw
BMW 91 / 99* C (180/195*F) dual temp switch Part #61311378073

here's a great link that describes it well : https://www.cherokeeforum.com/f51/taurus-fan-volvo-2-speed-relay-how-214815/

did you find your other answers in the docs ?