MoTeC Global Forum

hello,

i have a Motec M4 ECU and an AE86 i want to swap it with a 4age Blacktop but i have a few questions so i have some of you guys can help me out.

- i work wih COP now so no dizzy but where do i get my tachosignal from?
- what sensor do i need to use to wire up the fans (i already found the setting in the ECU itself)
- i have a O2 sensor but it has 4 wires (+, -, OX and HT) in the M4 manuals the motec only has 2 connections... how do i wire this up?
- what input do i need to use for the VVT?
- is it possible to have launchcontrol with an M4?

I really hope someone can help me out.

Hi,
This has been done many times.

COP's will work (preferentially with inbuilt igniter's) but you will need to wire them as waste spark to save outputs for other things. A output on the ECU can be configured as tacho but the standard tacho is for coil negative so you will need to modify it to work off a 12V output signal from the M4.

You will not have enough outputs to run thermo fans from the ECU unless you use a IEX. See below:
CAM 1 output
Ignition 2 outputs
Fuel pump 1 output
Tacho signal 1 output

Using a IEX will save you one ignition output which can then be used for the thermo fan. You will not need extra sensor as the engine temp is used for fan control

Which lambda sensor do you have? There are drawings on the MoTeC website for narrow band and wide band sensors.

The VVT on a blacktop is either on or off so no sensor is required, just a output to switch it.

Yes launch control is possible, the ECU will need to have the advance tune upgrade.

The pin assignment above leaves no outputs for the Toyota Idle up solenoid which needs 2 outputs to correctly control it. If you want a Idle up solenoid then you will need to use a tachometric relay to drive the fuel pump, this way you can use the output to only drive the close side of the Toyota valve or change it to a one wire type valve.

hey, thanks for this lot of information

For the fan i will use an thermocontact instead of an output from the ecu. 4 outputs isnt that much so for tacho i will use this. Do u have any experience with this or think its a good idea?

https://www.autosportlabs.com/product/tach-adapter/

Now about the lambda sensor. Its still the oem one im using and its small band (+ , - , HT , OX) and the ECU only has 2 pins wich are optional: LA+ and LA- so wich ones do u think i have to wire with those?

Then another question i forgot to mention. What about the knock sensor?

The adapter looks like 4 diodes that "or" the ignition signals together to drive the tacho. This should work with coils that require short dwell times. I think you may still need to modify the tacho to work on a 5V IGN pulse.

The OEM lambda sensor will be a narrow band sensor and won't be much use for tuning purposes.

M4 is a 20+ year old ECU and does not have knock control. However you could use something like the MoTeC SKM and connect it to a analog input to retard the timing.

I know but i only use the narrow band lambda to drive it, for tuning on a dyno i'll use a wide band. Is that possible because thats what my teacher told me to do?

For constant throttle driving it can be used.