HELP! VFAD trouble
 

So i just removed my VFAD after reading all the threads. but...im having trouble now. everytime i put the car in neutral as im driving, the rpms, just keep going down to 0 and then the car stalls!. any ideas of what i might have done wrong?

the only thing i can think of is that i did not plug up the hose, would that do anything?

Did you plug the nipple behind the throttle body?
https://www.rx8club.com/attachment.p...1&d=1239247531

no i left part of the hose still on figuring i wouldnt need to plug it. should i jsut remove all of it?

You can remove all the hoses, just make sure the intake is capped.

okay. im going to try this tomrw hopefully it works..:fingersx:

I just capped the hose where it rests in front of the intake box in case I ever revert back to stock... no problems so far. I have seen 5-6 degree hotter temperatures though... will be making a custom cai shortly to get colder air

^^Yeah... as long as you cap the line going to the intake and not the line going to the VFAD actuator it'll work just fine too.

hmmm... now you got me thinking. when I removed the hose off the "mesh tube" that goes through the bumper, a vaccuum was released, so I figured capping it would be good. Do I actually have to take out all the crap under the intake box up to the uim to remove vfad?

and I capped it right after the actuator, yes...

https://www.rx8club.com/attachment.p...3&d=1239450871

You do not need to cap the actuator side of the line.
The VFAD valve needs vacuum to close, so just keeping that line "uncapped" is all you need.

Let me try to explain this better:
There are sections of hoses and hard lines in the VFAD assembly.
You also have a solenoid, vacuum chamber, and a one-way valve.
If you disconnect a hose anywhere in this assembly, you'll bleed off vacuum to the VFAD actuator and the valve will open.
The valve will remain open until vacuum is applied to the actuator.
This is why you do not need to cap the hose leading to the actuator, but the other side of the line needs to be capped so you don't introduce a vacuum leak to your intake.

There are many ways to do this instead of capping the nipple behind the throttle body (as I posted above).
Here are a couple examples:

You can remove the hose connecting to the solenoid (on the actuator side) and cap the nipple on the solenoid.
Attachment 141140

Or you can remove the hose from the vacuum chamber (on the actuator & solenoid side) and just cap the nipple on the vacuum chamber.
Attachment 141141

These are a couple examples just to visually show what side you need to worry about capping (which is the line leading to the intake).
The goal is to prevent vacuum from reaching the VFAD actuator (which closes the valve) and plugging the line leading to the intake (to prevent a vacuum leak).

But some like to just cap the nipple behind the throttle body and remove the rest of the line to make it look cleaner.

Oohhhhh... gotcha. So I need to uncap my capped line then...

Thanks for the excellent illustrations Jon :D:

You don't NEED to because you already bled the vacuum out of the actuator.
But capping it (on the actuator side) isn't going to do anything useful since you won't generate vacuum with the hose uncapped.

here we go... Im a bit vfad retarded

Attachment 279633

Edit: nvm just read your above post. Everything makes sense now lol. Thanks again ;)

I'm at work and can't view Photobucket pics, only attached pics.

Well you helped me figure it out anyway, thanks man :)

VFAD is a one way line, so just cap it anywhere, its same shit.

haha its makes sense now. i ended up just capping the nipple behind the throtle body and it works :D

i didnt cap mine at all... i left the line in the bumper and put a breather on the end of it... works perfect

Glad it worked out for you!
I always suggest capping behind the throttle body since its easy to explain to others.
Capping elsewhere in the VFAD assembly would involve knowing to cap the intake side and not the actuator side (which involves me drawing little illustrations like above :)).

So if you leave the nipple behind the throttle body, the VFAD will remain open?

Yes. The VFAD valve needs vacuum to close.
So if you remove the source of vacuum (intake) the valve can't close.

Oh i thought it was closed all the time and needed vacuum to open. I really don't wanna remove all that crap if I don't have to.

I made a DIY video explaining how to test the intake valves (VFAD, VDI, SSV, and APV).
You'll see that I used a vacuum pump to close the VFAD valve (the SSV and VDI are opposite and requires vacuum to open their valve).
https://www.rx8club.com/series-i-do-yourself-forum-73/diy-troubleshoot-intake-valves-174009/

:spank:

Oh damn.... :banghead:
Back to the video editing....
You were the first one to catch that!

Brettus- Thanks for catching my dumb-ass mistake.
I'm uploading the corrected video now.

thanks for the info

Jon316G,

Thanks for the info Mate!!!...
I don't want to unhook my VFAD.....just yet, .....BUT ......you have given me an idea....

I want your opinion on this...

You may not know this but Mazda in their wisdom????, No longer supply Vacuum nipples for each separate Rotor on the intake side ports, you know this is where dealers and Series I owners can Seafoam from...well what do 09 (Series II ) Owners Do???..

Is there any reason IYO why I could not use this Vacuum Nipple behind the Throttle Body?, the same one used for the VFAD..

I am thinking I could disconnect it and link in a temporary vacuum hose if I want to de-carb my Rotary???

What do you think Jon...will it work...where is RG when you want him...;)

Good thinking ASH... but there is one problem with that.
When you crank start the engine to decarb (ESS disconnected) the SSV and APV valves are closed.
As you know, the primary runners (which are always open) is at the "top" of the lower intake manifold.
So even if you pulled Seafoam into the intake from the VFAD nipple, wouldn't most of the fluid just run into the secondary and axillary runners?
And with the SSV and APV valves closed, nothing gets into the engine.

But you do raise a good question, what do the '09s do to decarb.
I'll have to think about this for a minute...

I am thinking of cleaning without the ESS disconnected, even thinking of doing the "water" steam Cleaning method???...Thoughts..

I really like the idea and principal of steam cleaning carbon off, as the method should remove built up carbon in very fine particles...almost in reverse to the original build up??

What about using the jet-air nozzle to spray the decarb into the engine?
Attachment 144716

Did not think of that Jon, what is it that attachés there "Jet Air" ??, I just want to check my parts info and see if 09's have it,...I guess they do?

Its one of the three hoses on the intake's flexible tube:
Attachment 144717

Is that the Air Valve Actuator pipe for Emissions?

If it is the 09's use some of those Vacuum pipes but the AVA has changed and is 09 specific?
But it looks like it still connects in that area, parts info does not show that angle of diagram

No... you're thinking of the ACV.

Through the opening in the pic above (which usually has a hose attached), it comes out of the two nozzles on the other side of the manifold:
Attachment 144718

Looks like that would do the job Ok Jon..?

I think so.
And what is nice is that you get both rotors at the same time unlike doing it through the maintenance ports where you have to do it one side at a time.

If I use the water or Seafoam method would the car still run OK with that Vac line temp disconnected??, at about 2000 RPM

Well... when you decarb, you don't want the car to start.
Remember, you spray the decarb fluid while cranking for 10 seconds.
Then you let it sit for an hour before starting the car.
This is why you disconnect the ESS.

Refresher... starting on page 7 of this TSP:
http://www.finishlineperformance.com...5-08-1883f.pdf

I capped mine near the removed VFAD actuator Jon just to keep out dirt in the unlikely case it's ever returned to stock. I didn't bother capping anywhere else and all is well.

Makes sense if you wanted to play it safe.

Should I still cap the intake side for any reason? Again, I've not had a problem.

btw: although your video now more properly cites inches of mercury vacuum, air pressure is still the motive force. We're not talking Stargate Zero Point Modules here. ;)

So the nipple behind your TB is "exposed"?
Many users who installed aftermarkets intakes and forgot this step reported having issues since you introduced a vacuum leak into the intake.

LOL.. I should have known better.
Just proves nobody is perfect ;)

Oh, I would never leave nipples 'exposed.' ;)

When I removed my VFAD I left all the vacuum piping in place and capped the end at the [former] VFAD actuator just to keep the line clean. This way I could simply remove the RB Duct, reinstall the VFAD and hook up the actuator line to get back to stock.

Note that I have my RB duct mated to my stock airbox.

so is that all? because i donno if the vfad is really open.

Just cap that nipple under the intake mainfold and you're done, Finish, DEAL !

no more questions.

Ok guys I got a cool video. Should I upload it to youtube then post it here? keep in mind I cant do this till I get home douh! lol