What's this actuator?

http://www.flickr.com/photos/49168103@N08/4521743009/

If I try to turn it by hand, it's very stiff. With the engine running, revving, idling, anything...I can't get it to move. If I turn it by hand with the engine running, no noticeable difference in idle or during revs.

On an 88 GTU, btw.

Also, does my NA 13B have a knock sensor that can go bad? The exhaust smells like the engine is running stupid-rich.

 

looks like the air control valve actuator, from my understanding n/a engines do not have a knock sensor only turbo engines.

 

It's one of the 5th and 6th port actuators. When the engine reaches a certain rpm which I believe is right around 3800 rpms, the actuators rotate allowing more air to flow in for more top end power. On the S4 this action is controlled by the back pressure of the exhaust. On the S5 models it is controlled by the emissions air pump. This is only available for the n/a engines thus the "6 port" term.

 

Doh! Ok.

Idea's to the rich smell? I'm trying to get to DMV to get it transferred to my name, then to smog shop to see if it fails or passes. I know that a piston engine that smells this rich doesn't pass.

 

If my O2 sensor is bad, the ecu will go into limp-mode and default to pig-rich, right?

How do test O2 sensor? Search time, brb.

Thanks Fonzi and Dexter, much appreciated!

 

^ nope o2 sensor is only involved in fuel calculation when cruising.

 

No such thing as limp mode on S4s. Just replace the 02 sensor. A brand new one is about $20. Simple things like changing the 02 sensor and spark plugs will help you pass the smog test. Are you talking about at idle? Normal idle is fairly rich on a rotary, but your main cat should be doing its job to cut down on the HC levels. Also, the 02 sensor is not used at idle; only under cruise conditions (such as the 15/25mph smog test).

 

You can tell I'm a noob (to rotaries), huh? Haha, thanks for bearing with me, guys! I've always loved the rotary design, concept and theory...this is just my first time hands on. I love learning.

Got new NGK's, but the dummy gave me all 9's instead of 7's and 9's. I didn't pay attention at the time until I got home to install them, then was too lazy to go back especially after reading here that all 9's runs fine. Will 7's in the leading position help me through smog?

Will get a new O2 sensor while I'm at it...preventative maintenance if nothing else.

Thanks again, Rocket and Will!

 

"...Also, the 02 sensor is not used at idle..." Then why did my car have a hard time starting/idling after I replaced mine? It wouldn't idle for crap until it ran with the new sensor for a bit. hmmmmmm....

 

Running 9s (colder) for leading plugs will end up fouling them faster, and starting may be a little more difficult. In brand new condition, I'd wouldn't say they'd hurt your chances on the smog test, but they'll foul much faster than the correct 7s.

http://www.ngksparkplugs.com/tech_su...2.asp?mode=nml

Coincidence. The 02 sensor has zip to do with idle. You can let you car idle, then unplug the sensor completely, and it won't skip a beat. Something else had to change for your idle to improve (TPS adjustment, variable resistor, fixed vac leak, reset ECU, etc...).

 

Sounds like the catalytic converter is bad and or the ACV and associated emissons devices are NOT working per FSM. Check 'em out in the FSM fuel and emissions section. Done

 

Wish I could change the title to something like, "88 GTU smells really rich?"

Anyways, got the BUR7EQ's in the leading positions. Runs a lot smoother. The 9's that came out, pretty new, were pretty carbon'd over.

Suggestions on getting the O2 sensor out without a O2 socket? Clip the wire and pull it out? That thing is in a hell of a spot!

 

DO NOT clip the wire untell it is OFF of the manifold. it will save you a bunch of trouble. for some reason i felt the o2 sensor on my car would come right out. so i cut the wire to splice into the new one....big mistake. i cant get it out now and i dont have an o2 sensor lol. everyone says they should be pretty easy to get to get out... but its a pretty hard to do on my 86 n/a. if i get mine out ill let you know how i did it:P good luck

 

Haha, I used a 15/16" socket. Oversized, I know, but that was the point. I just folded the wire over the sensor, used the over sized socket and voila!

 

Well...passed smog. BUR7EQ's in leading and BUR9EQ's in trailing. $35 wires (want better), new air filter, fresh oil change and coolant flush and new O2 sensor.

Apparently I have an exhaust leak up front, as the engine bay smokes a little. Kinda smoked up the small shop, but the computer read everything within spec!

Insurance and tags tomorrow! Woo!