Retaining Purge Control on Modular eMod11
 

I just want some clarification in regards of retaining evap purge control on eMod11. On the Eugene software on the wiring diagram window, looks like pin 3H (Purge Control) belongs to module 1 which is a open/spare module. Do I need to purchase a module to retrain purge control?

Ever figure this out? I'm interested in this as well... if it is possible to retain it without too much expense, that would be nice. Otherwise, I'll just go ahead and delete the components to make more space in the engine bay.

I just realized this same thing. The function is available under the "Function" tab under "Purge Valve". Does the eMod011 come with a small output module by default to control all those functions in the #3 harness plug? I think that it doesn't based on the fact that it does factory twins out of the box. The twin turbo control (not marked spare) could be used to the same output function. Anyone know how to switch the output for purge valve? See install pinout:

https://cimg4.ibsrv.net/gimg/www.rx7...7c497c459b.png

I have not tested or implemented this yet but doubling back to the topic...if you have eliminated double valve (or just plugged it) you can reuse the output pin (injector output 8) to control the Purge Solenoid.

To do so: Go to Outputs Tab -> Output section and select Injector 8. In the section on the right (Function Setup) click 'None', filter by 'purge' and select ''Purge valve duty". Then entry the PWM frequency. 25 Hz. I am not 100% on this value yet, I have a tech submission to Adaptronic for some reference.

Then to configure how it operates go to Functions Tab -> Special Functions Section -> Purge Control.

For the pinout, move the purge wire from Pin 3H to Output 8, Pin 3O. Note: This may require putting a new pin on (I need to go do this myself as I retained the purge solenoid on my single setup). If you don't want to do that or don't have any pins, use one of the other unused auxillary outputs as seen in Outputs Tab -> Output Section.

As a quick update for those are interested, Mark from Adaptronic has stated that the purge feature is not actually implemented (as indicated by the 'not implemented' when selecting "Purge valve duty" in the Outputs window). He said that Andy might be able to get it in for the next firmware release for the FD S6 Modular. I will update if I get any further information.

So.... to be clear, even though 'Purge Valve' appears as an operational function in the 'Functions' tab; Mark bench tested the feature, it is NOT implemented as of FW version 0.220. Hopefully it is coming soon.

If you want it... contact Adaptronic!

I spoke with Elliot from TurboSource stating that adding a module is not require for retaining the purge valve and that there isn't a base duty cycle set. Basically the tuner need to figure out when to switch the purge valve cycle duty and what. I hope this make sense.

Correct, an additional output module is not required (if you change the pin on the ECU and update it's output function).

For the next firmware release, Adaptronic is working on the OEM purge function (solenoid energized between 1500-3300 RPM under low/medium load) to be available. Mark indicated in an email that the functionality will for sure be in the next release. The ability to edit the duty cycle will still be available.

Great! Thanks for figuring this out guys, I was just getting to a point where I was going to take out the purge control stuff on my rebuild as I didn't want to have to buy an additional module to run it.. but if the feature is coming and I can reconfigure an injector output (i've deleted egr/aws/double throttle/etc) to run it, then I'll keep that stuff in and do that.

I stumbled across this thread in a Google search for "FD purge control solenoid." Does anyone actually know the conditions under which the stock ECU opens/closes the purge control solenoid? I assume it's load-based (RPM and/or MAP) and all I've found is "1500-3300 RPM under low/medium load" as stated above. Also, does anyone know if it's run at various duty cycles or if it's a simple on/off affair?

I was having an email discussion with Adaptronic to figure this out. There are several places in the factory service manual that specify the operation of the purge control system (page numbers refer to the 1993 FSM).

Purge System Overview F-129:
https://cimg3.ibsrv.net/gimg/www.rx7...9115a4e15e.png


Engine Output Operation Page Z-37:
https://cimg9.ibsrv.net/gimg/www.rx7...021f17fcba.png


Troubleshooting Page F-197:
https://cimg2.ibsrv.net/gimg/www.rx7...29f2e98b69.png



It seems that purge control system is enabled on an engine that is at operating temperature (say > 75-80*C ) between 1500-3300 RPM under low to medium load as pictured above. AKA cruising speeds while in vacuum. It is not stated at what rate the solenoid valve is run at but it does reference a voltage of 4-10V while operating. Duty cycle would be some where between 30%-70% increasing as the RPM increases? The duty frequency is also unknown at this time but Adaptronic recommended to start with 100 Hz and go from there (when the firmware is released). The solenoid used for purge control is different than all of the other ones in the rats nest.

Now, the way that it will be implemented (much like it appears to be implemented now yet is non functional in v0.220) is Adaptronic have minimum speed, minimum engine coolant temperature and a load table (most likely with MAP as one axis) and RPM as the other. You can then configure specify the duty cycle of the solenoid for a given MAP/RPM cell. You wouldn't want to enable purge control at idle as it would screw up idle speed/AFR and you wouldn't want any additional fuel possibly provided by the purge system during acceleration or WOT conditions AKA MAP building out of vacuum.

If running in 02 sensor closed loop mode, the ECU could apply a fuel trim adjustment at cruise speeds to maintain the target AFR while cruising. Or if running in open loop mode, the mixture might be slightly richer at cruise speeds. So if you target 14.7-15.0 AFR (1.0 or 1.03 lambda) for cruise cells, it should be pretty close to stoich. I obviously haven't been able to test how much the fuel vapors from the charcoal canister are affecting the target AFR.

I was told to me that Andy from Adaptronic has implemented the functionality into the next release of the software. Not sure when it will come out but I'm sure they would love for anyone willing to help test it to provide feedback. With this function in place, I don't know why anyone would opt for eliminating purge control on a single turbo setup or a simplified twins setup. Yes, the operation is categorized as emissions control but it does not negatively impact performance. And allows you to improve mileage as it burns fuel vapors which would have just been vented to the atmosphere!

I have tried figuring out some similar things myself. The goal is for 100% support of all OEM features on the ECU. Its doable :)
Keep us updated on the progress :D

My thread:
https://www.rx7club.com/adaptronic-e...dules-1123992/

Awesome, thanks! I missed the info on page Z-37. That at least narrows down the normal operating engine speed range. I wonder what the OEM ECU considers "medium load." It's probably based on a bunch of things like manifold pressure, throttle position, etc. Base frequency and duty cycle is something I'm still trying to figure out too. I've read you can find the base frequency by adjusting it until the solenoid makes the least amount of noise. Once that's done I suppose the duty cycle isn't that critical. As long as the valve is open at some point to purge the charcoal canister I think you're good. I'll probably start with 50% and may try the 30-70% range you mentioned. What's interesting is the variable voltage to the valve. Did the guys at Adaptronic mention anything about that or is the plan to feed it constant 12V switched voltage?

I should probably point out I don't have a FD nor am I running an Adaptronic ECU. I have a N/A FC with individual throttle bodies and I don't generate enough pre-TB vacuum to open the stock FC purge control valve. I'm running a Haltech PS1000 and I plan on running the FD purge valve with Haltech's "open loop boost control" output. This gives me the ability to set the purge valve duty cycles as a function of engine speed and manifold pressure. I also have the option of 5, 8, or 12V pullup so I may just try 8V based on the info from the FSM. The only downside is there's no water/coolant temperature control. The only way around that is to utilize another output as a coolant temperature switch to drive a relay or something.

They did not mention what the feed was going to be but they were referencing the FSM. I was a little confused myself and was wondering if the voltages (4V-10V) were the PWM representation through a DAC?

Ah, I didn't think of it that way. That could give some insight on the duty cycles the stock ECU uses. Assuming the minimum is 0V then the duty cycle is simply a ratio of the average voltage to the maximum voltage. So if the average voltage varies 4-10V and the maximum voltage is 12V then the duty cycle is 33-83%.

Has anyone made any headway with this? I've been running the OEM purge control valve with a base frequency of 100 Hz and varying duty cycle from 30-70%. For the most part everything appears to be working but I've caught the valve "stuck open" a few times. Sometimes it'll pull vacuum when it should be closed. I plan on swapping out the solenoid to see if that's the issue but I'm also wondering if anyone has narrowed in on the correct base frequency.

There is an actual Purge valve function now. Are you using it?

I am using the purge control function currently but I have not really spent a lot of time trying to track down if it's operating correctly. My car doesn't smell like fuel sitting in the garage and run closed loop fuel in cruise areas where purge control should be operating.

I'm actually not running an Adaptronic ECU but this is the only discussion I could find regarding the operation of the purge control solenoid. I figured Adaptronic finally got around to setting up the function but I haven't been able to find out any details.

I'm in the same boat. Aside from my solenoid sticking open sometimes (I've got a new one on order) it works when it should (1500-3300 RPM, -10 to -6 psi when water temperature is >180 degrees). I was hoping someone could confirm the base frequency Adaptronic went with. I don't have access to an oscilloscope (or a stock FD for that matter) to test the stock operation. 100 Hz seems to be working fine. I don't hear any excessive noise but I'm concerned about long-term durability of the solenoid if that's not the correct frequency.

Purge valve duty function in outputs description says:
[currently unimplemented]

So is it implemented or not if some see it working?

Yes the tool tip says this but it does indeed work... I use the function to control valves on my Rx8

So for those with the purge valve duty function enabled what settings are you using? The FD FSM is pretty clear at what RPM the purge solenoid is operating but isn't as clear as to what load. It just says "medium load." I'm curious how everyone has interpreted this.

https://cimg6.ibsrv.net/gimg/www.rx7...ee9b81879d.jpg

This is how I mapped the purge valve. I think might have to adjust 3-6PSig range.

How have these settings been working for you? Has anyone else successfully set this up and confirmed working?

Just playing Thread Necromancer here... So since the output for the Purge varve is shared with Small module 1, is there a way to program a different output to perform the same function if using an internal Lambda module?