VFAD Solenoid Valve
 

Is there power at this connector at all times that the ignition is in the on position? I'm curious if I could use it to power my Wideband.

https://www.rx8club.com/attachment.p...id=67626&stc=1

No the power is switched on and off by the pcm depending on conditions

Actually I looked at it when I was installing my wideband. I found a constant 12v signal on it, even with key off. So perhaps the ground is the switched wire. I ended up adding a relay and running the trigger signal to the ignition wire under the dash.

Thanks - I talked to Adrian and he used power from the cig lighter in the dash. I was just curious about this one because it's currently not being used with my REVi intake.

VFAD failure ?
 

How can you tell if the switch is working ? My valve allows air to pass through before installation and while at idle. I thought the valve only opened at 5500 rpms ? When I exceed 5500, my car cuts off as soon as I come to a stop. I am thinking that something is wrong with my VFAD since this happens only if I pass that 5500 rpm range where all the fun is. I am also getting a p0171 code. Any suggestions ?

You can remove it entirely. It's not a major part of the intake and probably not the cause of the issue.
It's possible your fuel pump is overheating. Does it restart easily?

VFAD Issue
 

[QUOTE=Loki;4913976]You can remove it entirely. It's not a major part of the intake and probably not the cause of the issue.
It's possible your fuel pump is overheating. Does it restart easily?[/QUOTE

No it doesn’t, I usually have to disconnect the battery and let the car sit for 30 minutes before it will start again.

If you don't disconnect the battery and just wait will it restart only after 30 mins?

Basically your 2 likely issues are either bad fuel pump or poor engine compression. Get compression tested, there's no point in fixing anything else if the engine is toast.

Thank you, I have an appointment with Rotor Piston Motorsport. They are the only rotary specialists in the area.
The engine is so strong when it is running 80 mph in 4th gear at 4800 rpm, so I don’t think it is compression. Starts are slow even with the new 2 kw starter, especially hot starts. I take her in Thursday.

Rotaries gain compression with rpm, so yes. At speed if feels fine but has difficulty starting especially when warm. Good luck either way.

Doesn’t sound good. Thanks

I disconnected my VFAD solenoid by just unplugging THE wiring plug at the source back in 2009.
So now the 'Flap' is permanently open all the time, meaning maximum air in intake is available all the time.
Frankly on this one I do not see the engineering point of this valve and flap, I am certain I will be corrected which is good :)

Thank you for your input. It just seems like the engine is getting to much air just before it cuts off. When you pull off from a stop or slow turn you can here the intake howling louder than normal, then at the next stop she cuts off. I thought it was a vacuum leak, so I thought the valve being stuck open could be the cause. I spoke with the rotary specialist over the phone and he believes it may be a fuel delivery problem because of the p0171 code that I am getting. I checked my fuel trim percentages and the were good numbers with the engine warm. (-4 short and 15 long).

The engine can't get more air than it needs, nothing is forcing air into it. If you hear howling try to figure out where it's coming from. It may be not getting enough fuel for the air it thinks it is getting though, which makes sense with the 15 long-term fuel trim. 15 is too high to be normal, you have a vacuum leak after the MAF sensor, so unmeasured air is getting in. Potentially the vacuum line to the VFAD has come off, the nipple is on the underside of the throttle body, out of sight.

Any obvious damage or gaps in the intake tract?

The howling is coming from the intake. No visible damage. It just makes more of a hollow sound than normal with no power, than it kicks in, but it will cut off at the next stop. I started it with no problem yesterday and it held idle at 850 rpm for a half hour.

I keep ready more and more threads and it sounds like the fuel pump is going. The rotary specialist is a hour and a half drive from me on the highway. I don’t feel comfortable trying to get it there, so I am going to replace the pump first. Any recommendations ?

Getting the fuel pump ring off is a little tricky, Mazda has a special tool for it. It's not impossible, but not enjoyable. See if a local Mazda dealer can do this for you?

Okay, Thanks