I got a problem with turning on the engine. Yesterday I turned it on and immediately the RPMS went wild up to about 4500. When I step on the pedal, it didn't help and the RPMs kept the high level. Second time was the same. Below I put photo of the carburator and I have a question. Should the choke plate (under my finger) be open when I start the engine or closed ? What about the second plate ? One more thing, when I turned off the engine both plates are fully closed. The accelarate string that connects pedal with the carb works fine, I mean the spring works fine and the string goes back to its original position after pulling it manualy.



Do You know maybe wht the problem may be about ?

 

When the engine is cold the choke butterfly will be closed. As the motor's temperature goes up the butterfly will gradually open, letting in more air. When the engine reaches it's operating temperature, the choke butterfly will open up all the way. But that being said, I don't think its a choke problem. I think you have a vacuum leak someplace, either a line has come loose or developed a hole or tear, or a gasket may have went bad and is leaking vacuum. It can leak between your carb and intake or between your intake and heads. Make sure all the unused ports on the carburetor (if any) are plugged off. They sell a container of different size "vacuum caps" at your local parts store.

All of a sudden idling real fast is one of the signs of a vacuum leak. There could also be something binding the linkage and keeping it from going back all the way. If you don't have any vacuum hoses off or torn, try starting the car and pushing the throttle linkage toward the back of the car (this closes it) and see if the rpms go down. If the rpms go down, then back up once you let go, something is holding the throttle open like a choke linkage or something. I'm not too big on quadrajets, I've had 3 of them and they were all junk so I'm not familiar with the way the choke linkages work on them.
Oh yeah, Quadrajets have a choke pull-off. This is the little thing on the passenger side of the carb. When you start the motor the choke pull-off keeps the secondary air doors (butterflies on the back barrels) shut while the engine is trying to start. Once the engine starts the pull-off uses engine vacuum to basically unlock the air doors. You can see the choke pull-off in the picture, it has a green rod hooked to it. Check the pull-off (the round thing with green rod coming out of it) have somebody start the car while you're watching the pull-off. When it fires up the pull-off should pull that rod towards the front of the car. I don't know if the pull-off would make it run wide open but it's ran off engine vacuum. I may be wrong about the whole vacuum thing but it's something you could try if theres nothing wrong with the throttle linkage.