I spent 2 hours today with my dad messing with the carb on my 84. Well, I got it to idle like it should. About 800 with the AC off and 1100 with the AC on. However, the thing STILL runs rough. The idle skips around about 150 rpms. It has a new air filter and the oil was replaced about 300 miles ago so the oil filter is new. I dont think it is bad fuel because it has been doing this for about 4 weeks now. I have plenty of power and it seems to drive fine..its just it idles REAL rough. When I listen to the exaust i can kinda hear a puff puff puff puff sound commin from it. Its hard to explain..kinda like a odd suckin noise. Also, when I hit like 1000rpm I hear this like huge resoance. Like some piece of metal is going WHOOOAAAAA noononononoOo!!!! and vibrating like a mother...BUT below or above 100rpm it sounds just fine..hehe. So what could be the culprit on the rough idle. Spark Plugs and cables? And anybody ever had that wierd noise around 1k? WHen I hear it i THINK its on the driver side of that helps. And the noise seems to be comming from more under the driver side then in front of the engine.

 

spark or vacuum are my guesses. it should only take a second to pull the plugs and see how they look.

 

mine idles at about 500 and but bounces about 100 in each direction.

talk about a burbling idle. I get tons of guys comeing up to me asking " you got a v8 in that thing?"

I just reply "its a rotary, they sound alittle weird"
they just scratch there head and ask what a rotary and,well, you know how that story ends.

 

Try playing around with the mixture screw. Turn it clockwise(lean) till you hear the rpms start dropping then back out 1/4 of a turn.

 

I too think maybe a vacuum leak. But , if it has not been tuned in a long time Ie: ( plugs, wire, fuel filter , rotor cap, wires...etc...) I would do that. Also, like someone else said, adjustment screw. I had a high idle that I could not get to come down. it was a vacuume line...runs great now...

 

Just some wild thoughts? nosie fuel pump going? Sound maybe the shutter valve?

 

sounds like you have the same problem i had when i removed my rats nest,

did you remove your rats nest?

if so i know what the problem is and have been meaning to make a post of it but my digi cam took a dive on me so unitil i get a new one i can only draw a picture with words.

lmk

 

Norad if you are still having this problem, I Think i know what it is, warm up you car so it idles like normal, open the carb top, if you hear sucking you shouldn't try cover each hole with you finger, it should idle smoothly...in terms of fixing it im not too sure, plug it maybe, or get a new valve on the end of that hose..any ideas anyone?

 

Found out my shutter valve was shot by checking the hose that went to the AC should not be sucking air at idle and was. Plugged it and ran alot better. But tried to disconnect and plug the vacuum hose that goes to the shutter valve and it ran rough so switched it back. Kinda of odd.