MoTeC Global Forum

Hi

I'm using M800 and all 8 of Analog voltage pins are already occupied.
However some Analog Temperature input pins are still vacancy.
My question is, can I use these Analog temperature input pins for analog voltage input?

Please let me know

Av`s are pulled to 0v with 100kOhm
At`s are pulled to ov with 100kOhm AND to 5v with 1kOhm

If you want an extra AV you can use vancant lambda Vs pins, just remember is also have a very weak pullup to 5v 200kOhm

What do u want to use the AV`s for?

Hello Martin,

Thanks for reply.
At this time both Lambda Vs pins are already occupied for lambda meter input for both bank.

I'm setting ECU up for engine bench and I would add another input signal to force fuel cut.
I need to cut fuel very quick, even before overrun fuel cut work.
Also sometimes I need to cut fuel without throttle closed.
I would input the signal from bench control panel (5V or 12V or GND)

At this time vacant input pins are:
DIG 3,4
Lambda pump 1,2
AT 5,6

My idea was setting -100% in Fuel Comp2 map when fuel cut signal voltage comes on.
AT has 5V pullup with 1k ohm..
So, if I make AT pin connect to a relay to GND,
grounded=0V
open=5V?
if so, this should be good enough to work with...

The input signal should be OK with digital (on or off), so connecting to Digital input might also be possible.
However I have no idea how I can set it up in digital input setup and axis setup of comp2.

When I use digital input, function should be... monitor?
How I can specify Hi/Lo in axis setup?

No need to run your GND thru a relay...just ground AT5 and measure the voltage with the pin to decide when to switch. You can wire the Switched GND to AT5 and then then go into the "input Setup" set up a user channel1 to read AT5. select cal# 45....then select custom...table, set up as follows

0.00v to 3.000v = 1
3.001v to 5.00v = 0

Set up fuel comp2 to read "user 1" to decide if the fuel comp should be in.

axis setup> USer1

0= 0
1= -100%

Ive got a feeling that the table is not going to do for you what you want. If you put in -100% fuel i think it will still be backfiring and popping...maybe you can test it? I hope im wrong

And when you test it....Log it!

Cheers
Martin

Cool! thanks a lot for nice advice. it made sense.

When I logged with the other engine,
fuel effective pulse width was 0 while fuel cut input is active.
( I had vacant AV pin at that time, I used AV for user input)
However lambda meter read 30-50 AFR for couple seconds after fuel cut.
I guess the fuel came from returned blow-by from PCV and some residue in intake port though...
It might also be possible the fuel injection is not completely cut, as you mentioned

Thanks anyways, I will try it and will post what happened with this.
The test will be two weeks later, I'm working on wiring preparation...

Cheers

Just as a matter of interest, why do you want to force fuel cut? even before overrun?