I did some searching but couldn't get an exact answer. Should the vacuum hose from the manifold to the pressure sensor have a restictor in it? My car is an NA.

 

Yes...

 

It's called the pill.

 

Actually if you look at the Mazda parts catalogue it's called an "orifice".

 

is it possible to remove it without problems?

 

I always thought it was "the pill" I stand corrected.

 

Many people have reported driveability problems after replacing vac lines and forgeting or not knowing about the restrictor. This mainly seems to be with turbos though, dunno about NA's.

Why would you deliberately remove it anyway?

 

okey....i have a TII.
New silicone vac-hoses witch is slightly larger så I cant get the pill to be still in the vac-hose

 

The reason that 'pill' is there:

The rotary engine has some insanely strong intake and exhaust pulses
If you hook a vac gauge up to just pure vac, the needle will bounce like crazy.

You don't want the MAP sensor to pick up those fluctuations, you only want it to read the manifold pressure. So you put in that 'pill' to restrict the flow, smoothing it out.

Now, for you guys who need a new pill, go to an aquarium store and get an air preportioner valve. These are used for controlling the amount of air an airpump can send to one of those little air stones.
They tend to be T-shaped and have a little lever on top to adjust the amount of flow. If you have a vac gauge or a boost gauge that shows accurate vac, just adjust the valve untill the needle stops shaking, no more.

You can probably borrow a vac gauge from your mechanic if you dont have one, just for a minute.



The big bonus is that these preportioner valves tend to cost about $1.25. Don't forget to cap off the other side of the T if you are not using it.

 

Find some plastic or metal rod of a diameter that will sit snugly inside the vac line, cut a short 4-5mm length and drill a 0.5mm hole in it. That will work the same as the stock one.

 

I bought one a couple weeks ago and in stalled it. Let me find the thread with the p/n...

I see you must not have searched much, but anyhow:

https://www.rx7club.com/forum/showth...hlight=orifice

 

They have to use the right terminology......ORIFICE humor.

 

I actually made one out of a little wooden dowel once, with a 1/64" hole drilled through the center. Seemed to work OK until I found an OEM replacement. I didn't notice any change in the way of driveability when I drove mine around without the pill for a while. Orifice...Restrictor...Whatever...

 

I have a N/A car and have no problem with running without that thing.

 

thanks for all the info. Now I will be sure to replace it with the vaccuum line.