MoTeC Global Forum

I'm going to be running an M800 alongside the factory ECU in my Toyota Soarer V8 (supercharger on the way...), What I would like to do is log one of the factory ecu's injector outputs so I can compare it to what the Motec is doing.

It would also be great if the same thing could be done with one of the ignition outputs but i'm guessing it would require something more powerful like one of the dash's or new ecu's to calculate ignition timing?

If anyone has any tips, suggestions or a 1uz-fe base map I'd love to know about it!

Hi Allan !

In case you want to measure injector duty from de original ECu, I would splice injector signal wire passing throuh a resistor and go in to a Digital input of M800 ECU.. After that , I would logging this DIG input with highest rate to measure opening event injector time. .

PS.. Using 4K7 ohms resistor and maybe one more resistor like a pull-dowm (10k),,,just try it !

Thanks Gaston,

Sounds like a Plan!

Just to clarify:

With the ECU pulling the injectors to ground I need a Pull-up if the injector is disconnected from the stock ecu

Sound right to you?

next step would be finding something in the Motec data logs to compare it to or perhaps loop one of the motec injector inputs into another Digital in...

You can also use the digital input function for Cam Position to measure the factory Ignition timing, I have done this a number of times. Simply splice the factory ignition signal (from the ECU to the ignition module, not the high tension side) to a digital input and set it up as Cam Position. You have to use the falling edge and you will need to change the number of teeth to 4 as there are four ignition signals per 720 degrees, I asusme you are still using the factory twin distributors?

Last, you will have to set the offset parameter using a timing light to allign the ECUs measurment which what the factory ECU is doing, then drive around and use as much of the map as possible.

The MoTeC ECU always logs its own fuel pulse width and ignition timing so there is no need to loop it into a digital. You will need to log the Fuel Actual Pulse Width to compare it to the factory stuff. Fuel can be a bit interesting becasue there is no way to really work out what dead time extra pulse width Toyota adds.

Great stuff! Thanks Mark!

Yes I am running the the factory sensors and ignition, an attempt to not change anything under the bonnet so the factory ECU can be plugged back in and it will run.

Mark,
While I am getting the gist of it - but this could be a great as a webinar !

MarkMc wrote:You can also use the digital input function for Cam Position to measure the factory Ignition timing, I have done this a number of times. Simply splice the factory ignition signal (from the ECU to the ignition module, not the high tension side) to a digital input and set it up as Cam Position. You have to use the falling edge and you will need to change the number of teeth to 4 as there are four ignition signals per 720 degrees, I asusme you are still using the factory twin distributors?

So set the CRIP as per standard, and use the TP for Alpha-N - and it gets the cam position (IGN) saved somewhere?
But where is this saved to - or is it output as an engine channel?

MarkMc wrote: The MoTeC ECU always logs its own fuel pulse width and ignition timing so there is no need to loop it into a digital. You will need to log the Fuel Actual Pulse Width to compare it to the factory stuff.

Where is this logged to?

You log it......Fuel Actual Pulse Width is the channel so that's what you log. If you set the ignition measurment as a cam position you will have to assign it as a cam channel like left inlet, that would be the channel you log.

To get an idea of the ignition or fuel map you would also have to have a throttle position and manifold pressure sensor logged as well.

MarkMc wrote:You log it......Fuel Actual Pulse Width is the channel so that's what you log. If you set the ignition measurment as a cam position you will have to assign it as a cam channel like left inlet, that would be the channel you log.

To get an idea of the ignition or fuel map you would also have to have a throttle position and manifold pressure sensor logged as well.

Thanks Mark - I think I understand.
For an alpha-N I do not use MAP, just TP and RPM.
So I'll "T" the TP, Crank, and Cam sensors to go to the m800 along with them feeding into the existing ECU so the engine runs.
Then I will set the low side coil, from a wasted-spark, as falling edge (This is on an inline-4 using 2 coils) - I guess one per 360 - so not sue if that conflict s with the cam and crank. The engine will look like a 4 stroke for CRIP, but a 2 stroke for the spark (cam1).

I am not sure how to log fuel pulse width as only the standard ECU is running the engine???
But nutting it out I think I hook up one injector with an inline resistor to cam2 input. Assuming the voltage is high when the injector is shut (sync-current)... Then logging the falling edge we get the injector start(?).
Then "T" that same injector over to the cam3 input and log the rising edge of the very same injector to get the injector ending.
Then we have injector on-time (plus dead-time), as well as the phase that the injector is set relative to the crank(?)

Do I have this right?

All that would be left then is to run the thing hither and yon at all RPM and all throttle positions, to get a pretty sampling over the map.
And then remove from each map cell the dead time of the injector which I can surely find or measure.
Then I switch ECUs and I am pretty close to the existing ECU as a base tune?

Well after a weekend of tracing wires (seems a pinout for the 09/96 soarer v8 ecu does not exist ) It's in!

Crank and cam trigger working fine and clean.

TPS and air temp seem fine, plugging the water temp in causes the factory ecu to fall over will try it on an AV in rather then AT and see if it behaves...

A lesson I got on the weekend "always run more wires then you need" so next weekend will be running more wires and replacing jaycar wire with Tefzel!

Still after a 1UZ base map if anyone has it!

To be honest we have never had much worthwhile success with trying to "sniff" a factory fuel map from a standard ECU, the ignition timing is worthwhile though. I think it's probably more worthwhile logging the ignition timing and Lambda and as many other sensors as you can (engine temp, air temp, etc) so when you go to tune it on the MoTeC you know where the factory level is at.....I would rather just tune it anyway but it is interesting to see what the factory does.