Evo gp wiring and advice on idle valve

For Mitsubishi Technical Chat
Post Reply
gaz@gr
Posts: 15
Joined: Wed May 16, 2012 8:12 pm

Evo gp wiring and advice on idle valve

Post by gaz@gr » Sun Jan 20, 2013 10:59 am

What i can establish from the evo pnp pinouts is all idle valve wires go to one output and its called a linear idle .

On a earlier setup i used 4 outputs , can i ask why its better than obv reasons of freeing up outputs.

How do i control the valve in the syvecs scal ?

thanks

gaz

pat
Syvecs Staff - Cleaner
Posts: 354
Joined: Fri May 23, 2008 9:23 am
Location: Out there... somewhere
Contact:

Re: Evo gp wiring and advice on idle valve

Post by pat » Tue Jan 22, 2013 6:41 pm

Gaz,

On the Evo PnP we decided to not criple the ECU by using up four otherwise very useful outputs just to implement something as basic as idle control. To this end we took the IGN6 signal (if memory serves) and that goes into a "quadrature decoder", that is to say we send a PWM signal to a decoder chip which then decides what the duty cycle of that signal is, then computes what the desired step position is and if different from the current step position it will then sequence the four idle outputs in the correct sequence to get to where we need to be.

The "quadrature" term is an old thing that is a misnomer because there is no quadrature in use here. In an earlier design we used TWO ignition outputs for this function, and depending on the sequence they were changed in, would cause the decoder to move the stepper forward or backward, all the while still having the full step position control in the S6, BUT that was wasteful AND the decoder chip had enough grunt to decode a PWM signal so we went for that in the end.... but you will see some reference to "quadrature" in some of the docs.... I should really amend that!

Now the LINEAR IDLE you are referring to is just that... there is an option to control the STEP1 output from either the output of the decoder chip or directly from IGN6. What this means is that if you have thrown away the stepper and you're using (say) a Bosch valve, you can still use the STEP1 output to drive it but now, instead of it being a sequenced stepper output it is a true PWM output that can drive a linear idle valve like the Bosch units. Most people will never use this. But let's say you want to run a GEMA engine, whereby the idle is most likely done by DBW.... then re-using the erstwhile idle output to control the DBW is most useful. Indeed we have the ability to take IGN6 as a TTL signal as well (but not via STEP1). So you can use IGN6 as either a) 4 stepper outputs that are sequenced based on PWM duty or b) as an open collector output capable of sinking about 1A with PWM control or c) direct TTL drive.

How you control your idle valve will depend on what valve you actually have. If you still have the stepper then you will need to use four outputs on a GP (we will be releasing a stand alone decoder / driver for steppers in the future).You will need to configure the Idle Stepper strategy for this. If you have a Bosch type valve then you can just use one of the AUX outputs for it, and you would not use the Idle Stepper but the Throttle Bypass Valve strategy in this case (indeed on the S6PnP we use the TBV even though there is a stepper, since that is decoded externally).

Hope this helps,

Pat.

gaz@gr
Posts: 15
Joined: Wed May 16, 2012 8:12 pm

Re: Evo gp wiring and advice on idle valve

Post by gaz@gr » Mon Feb 04, 2013 9:20 pm

First of all thanks pat

So if on pnp a controller is available when will it be released for gp ?

To be honest i dont do get how to set the stepper motor up . I have used 4 outputs and I am sure they are pinned correctly .

Is there a way of checking this ? I have done it via a cal u sent me almost 2 years go . Anything i adjust in the software has no real effect .

The car idle is low basically , target is 1000 rpm and idles around 900 when warm .
The 2nd problem is the cold start it would be nice to achieve a slightly higher idle at cooler engine coolant temps decaying away as temps rise .

i have used the closed loop idle section to a extent controlling via timing ,but i am sure you might be able to point me in the right direction to get some control over this std valve .

any help is appreciated pat or anyone else

thanks

gaz

Post Reply