mwpayne

Hey Guys (& at least one gal)

Got the 85 to idle somewhat, saw a thread about if the hose going to the shutter valve is pulling during idle, it's bad. I plugged it, it runs 100% better! No more hesitation & surging at low RPM's. Can I leave it plugged? What's the thing do, anyway? Idles somewhat smoothly (1700 rpm, still can't find the
&*$# adjustment screws)!
Gettin' better all the time, thanks all!

Blitz0309

mines plugged...

SilverRocket

on mine there were are 2 openings, I plugged the big (left) one and left the small (right) one unplugged

SuperPhly

So it's ok to plug the big shutter valve line?

Pele

iTrader: (28)

Some of us plug it. Some of us remove it from teh intake entirely and block off the hole. Some of us remove the carb and intake to replace the valve.

Aside from the latter, there are very minor side effects. The most noticable is small backfiring on deceleration. There may also be a change in fuel economy and power. It will probably improve over having it unplugged, however I am not sure how plugged compares to stock.

SuperPhly

hmm, i;ll go look at my haynes and try to figure out which one it is... and then find a way to plug it

Wish me luck!

Pele

iTrader: (28)

It's this one.

MIKE-P-28

iTrader: (1)

Everyone I ever had got removed, this is a BAD BAD BAD thing mazda put on our cars! Its job is to close the flap and not allow any air/fuel mixture to the rear rotor during deceleration, in my opinion this is BAD. I just jerk it off all the lines, flap and all, and get a plug the hole into the intake manifold.

BYE BYE POS

Any connection to this and 85% of all rotary engines having a bad rear rotor upon rebuild?

dcamcoTII

So all you need to do is just plug the hole inside the airbox, and the valve is disabled?? Also, would a bad shutter valve cause the car to not idle at all?

dcamcoTII

Bump, I have a car that wont idle at all under 2k. Perhaps a shutter valve problem?

WackyRotary

I have to agree with Mike-128. I also believe that this shutter valve is responsibly for cutting the metering oil from entering the rear chamber during deselsertion over 100,000miles of a single engine life is bad. Usually in-town driving is what caused the problems for it or letting off the gas for long periods cuts the oil metering from entering effectively. I know there is a tiny hole in the butterfly of that shutter valve, but don't believe its really effective in getting the oil in when above the hole is a void in the carb bore so its not really drawn in.

Over the years, i have noted that the rear housings in most engines I've messed with(stock running 12a with Nikki completely stock that is in high mile form) generally are not as usable or not usable at all. They usually have more crom flaking with out question IN MY experence that is.