My rx7 failed smog it was a gross polluter. I took it to mazda dealer to have it diagnosed, they said the ACV valve was stuck open. is it possible to free the valve or would I just be better off buying a new valve ... if so how much would it cost me to buy a new valve? MAzda dealer wanted to charge me 750.00 to put a new ACV Valve and choke plate.

 

I valued my ACV SOOO MUCH that i threw it in the garbage ages ago.



sorry man if i'd known i'd give it to ya!!!

 

so nobody knows??????

 

I thought there would at least be someone on here he knew something about it??

 

its prolly bad. there 2 vacuum diaphrams in there that dies with heat and age



mike

 

I have the acv that I removed from my 85 with 147,000 miles. The electrical connection had been cut when I purchased the car. I will have to look and see if I think it can be used. I really don't know the condition of it but you are welcome to it...just cover shipping from 28803.

Heath

morganf1@aol.com

828-275-1127

 

whats an acv valve? Air Conditioning Valve? Air Control Valve? where is it located?







late

 

air control valve, its bolted to the side of the intake manifold



mike

 

oh, where that plate is. ok

 

You can take a look at the diaphragm by unbolting the first round diaphragm chamber on the ACV closest to the air pump. There are four bolts. This is the one that controls whether the air goes to the catalytic converter/exhaust manifold or to back to the air cleaner. The air needs to be going to the cat/exh. manifold for emissions equipment to work.



In my case the rubber diaphragm had gotten very hard and would not flex. When I did flex it it cracked. You probably just need to replace the diaphragm. If you are buying a used part take a look at these diaphragms for holes and flexibility. Be careful as there is a spring and some oil inside but it is no big deal.



You should also check to see if you are getting vacuum to the valve. It is controlled by the second solenoid valve closest to the firewall. Disconnect the bottom hose on the solenoid and connect a longer tube to it and when the motor is running, apply some suction. While you are doing that check to see if the tube running from the ACV to the air cleaner is flow any amount of air. If it is then the valve is bad, if it is not then it could be a vacuum or solenoid problem.



The dealer (USA) wanted about $400 for a new one. A used one can cost around $75 to $100 if you can find one.



BTW - You can find an 1985 RX-7 manual somewhere on the net and it details some troubleshooting steps for the emissions.



Hope this helps.