well today I tried to fix my idle problem( car was idleing at 1500 rpms) so I took off the intake tubing and when I pulled off the intake elbow I found that this is broken







I talking about the plastic tube with the green strip. it is connected to the thing on the side of the tb and my first set of butterflies is stuck open. I hope that this is not going to mess any thing up. also when I start my car up I have to give it some gas or it will stall out I only have to touch it lightely once to keep from stalling chould this be affecting it?

 

I'm not sure about the tube as I have removed all that crap, but the throttle butterflies "stuck" open is fine. It was probably done by a previous owner as part of the throttle body mod. It doesn't really do anything on an NA engine, but its not going to cause any problems. Those butterflies are normally closed when the engine is cold and open when the engine is warm to protect the engine from over-use when cold.

 

sorry but the butterflies are not ''stuck'' so to say. I can make them close by hand no problem but they spring open as soon as I lit go. and the PO was an old lady so the throttle body dose not have any mods. and I still have not fixed my idle problem this car is my DD so I cant take off the TB to check the thermowax. I tried to adjust the idle by turning the screw on top of the TB ( if you look in the last pic it is under the black rubber cap on top of the throttle body) and the car just starts having a bad misfire but then I back the screw off the car starts to run fine but has a high idle.

 

On the TB down to the right of the primary throttle plate, is that a dent in the o-ring channel I see?

 

no the PO thought it was a good idea to glue in the o-ring.

 

Actually mazda glued the o-ring. But on the right side of the o-ring, the cast looks broken

 

Those butterflies stay open until the engine is started and vacuum is applied to the actuator to close them. When vacuum drops under acceleration, they open gradually to prevent a sudden rush of air when the throttle plates open. Mine stay open due to a leaky actuator and it runs fine. You could remove the vacuum hose entirely and cap off the vacuum nipple and you'd be fine. You may have a vacuum leak at that hose right now, contributing to your idle problem.

 

how whould I fix the vacuum leak at the hose. just cap it off or what?

 

If you look at the back of the throttle body (near the firewall) that hose should connect to a plastic thermal vacuum valve. Disconnect the hose from it and cap the valve nipple with a rubber plug from a parts store. Disconnect the other piece of hose from the actuator. You can cap it also for looks, but it isn't necessary.

 

ok thanks for the help.