Are you able to view pictures in attachment form? I can probably explain it, I got a open vacuum hose sitting in the front of my airbox and its the VFAD hose were assuming.

 

Jon - The photo is of a vacuum line being pinched/capped off in front of the airbox.

 

Yeah... that looks like the line for the VFAD.
Looks like someone disconnected it to keep the valve open, but possibly introduced a leak by not properly "sealing" it.
This is why we suggest capping the VFAD nipple... easy to reach and secure:

 

Alright!

Just follow this where it concerns the VFAD. Only reall page 3, that's all ya need!

It will also show you in a pic....exactly where the nipple goes on the throttle body!



Sorry Jon...we were typing at the same time! That's a pretty pic though................saved for future use!

 

yeah the plugs and wires went on with ease! Coils are happening at the end of the week as well as fixing this vacuum leak. I thought I broke my coils at first though, the top of it came off with my old wires so I just put the parts that came off back on and it worked.

 

That's scary...............the top of what came off?

I wanna make sure it's safe to drive!

 

The like rubber post on top of the coils, they just pop off and on. The part that when their off you can see the spring. I was scared that I couldnt use my car for a week, but seems like all is well, she pulls a lot harder now and no codes has been thrown.

By the way what size is the vacuum hose? So I know what size cap to get.

 

Best bet like someone said, is just to by a pack of them at Autozone. They are cheap and you will probably need more down the road! One I bought had like five or six different sizes and were black on a plastic tree sort of arrangment.

 

Here's a couple of pics of the VFAD vacuum nipple.

 

Thanks guys, you all are big help. On my other cars I didnt really wrench on them (only for simple stuff) but it feels good to wrench, im starting to learn and know my car inside out and it feels good to do your own work and accomplish them.

 

Hmm I can't seem to get the line off nipple. I'm scared to break the plastic nipple. Plus the line is like bungee. It just stretches.

 

Yea...it's a real PITA. You can also try the VFAD side of the one-way check valve.

 

+1
DeViLbOi is giving you a very safe alternative.

To remove the vacuum lines:
A flat screwdriver can be used to gently push down the rubber tubing from the plastic of the UIM.
This will deform the rubber and effectively loosen its grip on the nipple.
Once this happens you can gently twist it off without pulling the tube.

- It works sort of like a Chinese finger puzzle.

 

I can't take credit for that one either. Learned it from Jon when we were talking about doing mine.

 

Yeah, Jon is the resident expert for all things intake and vacuum related

The real PITA is pulling the caps from the LIM for seafoam when your engine is super hot

 

Hmmm okay ill try all of that later. Do you think its easier to take off while car is warm or when its cold?

 

Jon really knows his stuff and is probably single handedly responsible for 99% of the things I have learned about the RX8. If he doesn't know something though, he will tear it apart until he figures it out and there are very few people like that. Our local group, and I would argue the RX8 community as a whole, has benefitted so much from having Jon around a bunch of dorritoheads like us. Jon...I love you man! :P

Cold by far...who wants to burn their hands?

 

not to the point of burning, like just shutting it off, i meant warm. Oh well that was a stupid question anyways lol

and I totally agree, every thread I read about regarding technical stuff, I see Jon's posts helping them out. He really does know his stuff.

 

FYI............it doesn't have to be a screwdriver to work that hose off. I have a wooden skewer sort of thing that I like to use as it doesn't allow me to use too much force like a metal object. Anyway, all you really want to do is get something between the nipple and the hose. Then sort of work it down a little bit at a time and around the nipple slowly WITHOUT putting any prying pressure on the plastic nipple itself. Once you get whatever it is worked down and around enough, eventually the hose will come off with slight twisting motion. A small flathead does probably work the best as long as you don't poke it through the hose, or use it as a pry tool and bust the nipple.

 

"Expert" might be a little too generous... more like lucky (or unlucky) enough to have multiple hands-on troubleshooting experiences with various components.
I too still have a lot to learn...

I think Jocelyn might get jealous.
Though your comment scares me... why you sucking up... what do you have planned for me to work on now

 

jayscoobs- I've gotten pretty good at taking off stuck caps and hoses using wide grip pliers.
Don't pinch the hose tight, just a small amount of "grip" so that you can twist/rotate the cap.
Once you can get the cap to rotate back and forth, start pulling away while still twisting the cap.

 

On a vacuum related note, I am getting a tune from Mazdamaniac and after my first datalog he noticed a considerable amount of fuel trim and suggested that I may have a vacuum leak. My question is, is there a procedure to follow to diagnose where the leak is?

 

Use a vacuum gauge to measure the in.Mg at the VFAD nipple with the car running.
Knowing how much you get will indicate if there is a leak.
But it also helps narrow it down (if there is a vacuum leak) because there are a few lines (SSV, VDI, VFAD) that are normally closed at idle.
The AIR solenoid is fired for the 1st ~60sec when the car is started, so if you show low vacuum at first, then it goes up once the air pump shuts off, that REALLY narrows it down.

Sure you can look at every hose for cracks and such, but that can be difficult and easily overlooked.

 

This method actually worked best for me. Tried pliers but couldnt seem to get it to grip tight enough, I was afraid to grip too tight. What I did is I used the smallest flathead screwdriver I can find and carefully put it in the hose with no pressure to the nipple and worked it down. Came off with ease. I left all the other VFAD equipment on for now until I get my coil packs since im going to be taking the airbox off for that.

 

Resurrecting my thread so I dont open a new one, plus it makes it easier for the people that were following my thread and helping me on it. Now to the problems.

I got my coils last weekend and installed them. I also cleaned the MAF and TB, removed all the other VFAD components except for the solenoid with the sensor for it. Apparently the actual VFAD itself wasnt there which is why I had that open vacuum in the first place.

Okay, now one week of driving, my idleing is still dipping and causing engine vibration. I want to just ignore it but I cant and I feel like im going to be hunting down the problem forever. I also have like a metal on metal screeching noise when im revving her really high and sometimes on cruising. Maybe a motor mount?