pcv valve questions

[jacobdavis1979]

Ok ive had the 350 in the malibu for about 2 years i think. Im just shy of putting 10,000 miles on it and its ran like a champ im not really having in problems with it but i just now got around to putting a pcv valve on it till now ive just had 2 breathers. Yes its a new valve and hose. My problem is when i put it on it ran like utter crap untill i retuned the carburetor now its back to running like a champ. It wasnt missfireing or anything it was just idling bad.

My question is this normal or is it possible i got a deffective valve? Or am i paranoid? lol

 

[Fox80]

Where did you plug the hose from the valve into? If you used a large vacuum port on the carb that was capped of before it will change how it idles, in a way you created a vacuum leak, you are now allowing the vacuum the motor produces to pull neg. pressure on the crankcase, not a bad thing but the carb will have to be retuned to compensate for it. Most cars from this era just dumped the crankcase vapor from a breather on the left side valve cover into the air cleaner housing, the guy who owned my car before me did that with the right side as well, that basically acts like a breather but it burns the vapor off to keep free air emissions down.

 

[jacobdavis1979]

Yea it was the front port that was plugged
Ok cool thanks man I guess I was paranoid I got a deffective valve lol

 

[Clone TIE Pilot]

There are also different flow rates with different PCV valves. Alot of cheap aftermarket PCV valves flow too much and lean out your air fuel mixture.