Link G4X Plug and Play Evo 1-3 ECU

[Venomancer]

Hello everyone. I'm new to the programmable ECU game, but I like to tinker with things and have some basic knowledge about tuning, however, I would like to ask you a question. Is it possible to assign an engine attribute to a particular "NC" pin via the software? Let's say I want to assign a second oxygen sensor to an "NC" pin 55. Is this possible and how to do it?
 

[Adamw]

NC means not connected.  You can re-assign most IO within their scope of hardware functionality.  You can have up to 8 lambda probes, but you would be better using CAN bus in that case.  What are you trying to achieve? 

[Venomancer]

I will try to run my 3000GT with the Link G4X for the EVO 1-3, but it has 2 oxygen sensors, which are connected to pins 55 and 56. The Link has Oxygene to 56, but 55 is NC.

Btw if you or anyone else has a good running map for the stock 3000GT, I am willing to pay for it.

[koracing]

Can you send me the pinout of your ECU if you have it?

[Venomancer]

9 minutes ago, koracing said:

Can you send me the pinout of your ECU if you have it?

I have a general Pinout for the 91-93 3000GT Turbo. I'm not 100% if my particular ECU is the same.

3s_1991-1993_ecu_pins.xls

[Adamw]

The stock O2 sensors are narrowband so not much use to you unless you have a catalytic converter and have some emissions regulations to meet.  But if you want to use them then you can connect the 2nd one to any spare analog input.  If you want dual bank closed loop then I would suggest 2 CAN based wideband lambda devices.  

[Venomancer]

18 hours ago, Adamw said:

The stock O2 sensors are narrowband so not much use to you unless you have a catalytic converter and have some emissions regulations to meet.  But if you want to use them then you can connect the 2nd one to any spare analog input.  If you want dual bank closed loop then I would suggest 2 CAN based wideband lambda devices.  

Thank you for the advice. I have an AEM Uego X-series from my previous build that is still on the car. Is it possible to connect it to the Link ECU or not?

[Adamw]

Yes, you can connect it via CAN bus (most accurate) or using an analog input such as pin 56.  

[koracing]

I vote for CAN connectivity.  

[Venomancer]

Hello again. So I have managed to get the engine up and running, but it behaves very strange and I can't figure out why.

When I drive and get on the gas to build more load, the fuel mixture becomes leaner and leaner the more load there is. Vice versa, when there is less and less load, the fuel mixture becomes richer and richer until eventually goes to 9. Can this be from an improper setup on the MAP sensor or a bad vacuum hose that's running to the MAP? 

Also when I press the gas pedal fast, the car stalls for a second and then revs. However, this seems like has gone away from itself... 

I haven't connected the lambda to the ECU but monitor it from my cockpit. Can this also be an issue?
I attach the base map and a log of the car running if someone can help me figure out the problem.

Also, I have a question about some pinouts. I had to physically change the pin for Ignition 3 because I didn't find a way to do it from the software. Am I missing something or is it not possible to change that from the software?

3000GT.pclx PC Datalog - 2023-06-18 11;11;00 pm.llgx

[Adamw]

1 hour ago, Venomancer said:

When I drive and get on the gas to build more load, the fuel mixture becomes leaner and leaner the more load there is. Vice versa, when there is less and less load, the fuel mixture becomes richer and richer until eventually goes to 9. Can this be from an improper setup on the MAP sensor or a bad vacuum hose that's running to the MAP? 

Does your car have the 2 speed fuel pump on pin 21?

 

1 hour ago, Venomancer said:

Also when I press the gas pedal fast, the car stalls for a second and then revs. However, this seems like has gone away from itself... 

Your accel enrichment cold correction table is zeroed out.  The smallest value in there should be 1. 

 

1 hour ago, Venomancer said:

Also, I have a question about some pinouts. I had to physically change the pin for Ignition 3 because I didn't find a way to do it from the software. Am I missing something or is it not possible to change that from the software?

You need to change the wiring to suit the ecu, this is why it is sold as an Evo3 ecu and not a 3000GT ecu.  

[Venomancer]

9 hours ago, Adamw said:

Does your car have the 2 speed fuel pump on pin 21?

No, my car has a hotwired Walbro 450LPH fuel pump and Deatschwerks FPR, running 43PSI base pressure.

 

9 hours ago, Adamw said:

Your accel enrichment cold correction table is zeroed out.  The smallest value in there should be 1.

Thank you for noticing!

 

9 hours ago, Adamw said:

You need to change the wiring to suit the ecu, this is why it is sold as an Evo3 ecu and not a 3000GT ecu. 

Yes, I completely understand that but thought the pins can be changed via the software.

[Confused]

A number of pin functions can be changed through software, but not Injectors and Ignition drivers that are being used for Injection and Ignition. So, Injectors must be pinned to Injector 1-X outputs, and Ignition must be pinned to Ignition 1-X outputs, and you can't skip over any (i.e. you can't use Ignition 1-3, then 5-7, you must use Ignition 1-6)

 

Whenever you use a vehicle specific ECU in a different vehicle, it's your responsibility to match the car's wiring to the ECU. 

[Venomancer]

23 minutes ago, Confused said:

A number of pin functions can be changed through software, but not Injectors and Ignition drivers that are being used for Injection and Ignition. So, Injectors must be pinned to Injector 1-X outputs, and Ignition must be pinned to Ignition 1-X outputs, and you can't skip over any (i.e. you can't use Ignition 1-3, then 5-7, you must use Ignition 1-6)

 

Whenever you use a vehicle specific ECU in a different vehicle, it's your responsibility to match the car's wiring to the ECU. 

Got it!

[castillaricardo]

Awesome to see a 3000GT getting a Link. Do you have a thread on 3si or here about the install? I would like to checkout your progress and outcome.

[Venomancer]

18 hours ago, castillaricardo said:

Awesome to see a 3000GT getting a Link. Do you have a thread on 3si or here about the install? I would like to checkout your progress and outcome.

I will be making a post once I manage to get everything going as it should.

[Venomancer]

Ok, so far I have managed to normalise idle and get a steady cruise tune to be able to move the car around. However, I have one concern to dive into steady state fuel and ignition tuning and therefore full power tuning after that, because I do not have a pair of knock monitoring headphones and while I am aware of how to set up the knock detection, I'm not sure of what threshold and gain to use without being able to listen for knock.

Does anyone have any idea about the particular engine, a 6G72 Turbo in stock condition, what would be a good threshold and gain setting?

Also, I've calculated the knock frequency to be around the 6Khz mark, but I heard that the second harmonic at 12Khz is better to be used for knock monitoring.

I would be very glad if someone helps me with this.

[castillaricardo]

Have you sorted this @Venomancer? The only help I can offer is to use the timing from the ChromedECU ROM and reduce a few degrees off the boost areas. Datalog with those and note the knock threshold numbers. That should give you a safe threshold curve to start with. Unfortunately my stealth is not near me, otherwise I would offer to do a few pulls and datalog the spark timing I get from it. I could try to look for some old logs and get a histogram going if you haven't figured this out yet.

[Venomancer]

On 7/5/2023 at 8:10 PM, castillaricardo said:

Have you sorted this @Venomancer? The only help I can offer is to use the timing from the ChromedECU ROM and reduce a few degrees off the boost areas. Datalog with those and note the knock threshold numbers. That should give you a safe threshold curve to start with. Unfortunately my stealth is not near me, otherwise I would offer to do a few pulls and datalog the spark timing I get from it. I could try to look for some old logs and get a histogram going if you haven't figured this out yet.

Hey! I haven't had time to tinker with this. I copied the ChromedECU ignition degrees without reducing them, but I don't really go much into boost anyway, because I've put my solenoid at 0. I will install a knock-block that I purchased from Link and monitor the knock with headphones to see how the engine works with that timing once I have the time. Then I will set the threshold and call it a day. I will update once I figure everything out.