1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

won't idle

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Old May 17, 2006 | 10:00 PM
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won't idle

I'm very new to rx7's. This is my Dad's car that he's had since 1983. It's an 83 GSL maual trans, 12A. I have been trying to get it running. I don't know anything about this rx7. I have a 5.0 mustang that I race so I know about piston engines but nothing on wankles. The only thing I have done to this rx7 is change the plugs, wires, cap, rotor, and the battery. Everything else is factory. So with that in mind heres is the problem.

About 13 years ago he was coming off the turnpike and when he came to the toll booth the car sputtered, and died. he started it back up but it ran rough, like it had a miss. He tried a few things and then stored it. We moved so he drove it to our new house with the miss, cuz it was only 45 minutes and we followed him. It made it to the house and then we stored it again. So last year I started to mess with it. I tuned it up plugs, wires, ect.... The car will run, it will drive, but at idle it will hesitate, miss, and shut itself off. The plugs look fine, the rotor also good. I think the carb has to be rebuilt, its proly varnished up from old gas, but when the car started to run bad was 13 years ago. I don't know what could be the problem. My Dad doesn't know either, and he is trying not to take it a shop unless we absolutely have to. Any and all help would be appreciated. Thanks
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Old May 17, 2006 | 10:02 PM
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Do a search on "shutter valve" I'd bet its your problem.

Easy fix is to block the hose that comes into your aircleaner base closest to the driver's seat.
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Old May 17, 2006 | 10:08 PM
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Originally Posted by aussiesmg
Do a search on "shutter valve" I'd bet its your problem.

Easy fix is to block the hose that comes into your aircleaner base closest to the driver's seat.
is it a rubber hose or is it the large corigated hose that comes off of the exhaust manifold?
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Old May 17, 2006 | 10:18 PM
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rubber hose about 1" in diameter at the rear of the base of the aircleaner, block the hose, it'll make a world of difference.
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Old May 17, 2006 | 10:22 PM
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Originally Posted by aussiesmg
rubber hose about 1" in diameter at the rear of the base of the aircleaner, block the hose, it'll make a world of difference.
I have a mazda repair manual and I see where the shutter valve is. If the valve bad, where do I get a new one? btw it started doing this sputtering thing years ago, do you think it is still the same problem? what about the carb having to be rebuilt? Is that relevant or possibly necessary?
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Old May 17, 2006 | 10:26 PM
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Try blocking it first, then if the problem goes away and you are keeping it stock get a new one then.

If you're going to mod the car don't worry about replacing it.
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Old May 17, 2006 | 10:32 PM
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If the car has set that long, rebuilding the carb is a must in my mind, along with cleaning and purging the entire fuel system.
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Old May 17, 2006 | 10:35 PM
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Originally Posted by aussiesmg
Try blocking it first, then if the problem goes away and you are keeping it stock get a new one then.

If you're going to mod the car don't worry about replacing it.
this car is going to remain stock, do local auto part stores have them or is it a mazda only part?
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Old May 18, 2006 | 01:50 AM
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I forget which part controls the shutter valve, but you can probably pick one up from a member who is running a stripped down carb and save yourself a bundle from the Mazda dealer.
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Old May 18, 2006 | 01:59 AM
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a rebuild to the carb couldnt hurt in any case, they are a little tricky to do but you will manage
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Old May 18, 2006 | 02:01 AM
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Originally Posted by Jeff 86
I'm very new to rx7's. This is my Dad's car that he's had since 1983. It's an 83 GSL maual trans, 12A. I have been trying to get it running. I don't know anything about this rx7. I have a 5.0 mustang that I race so I know about piston engines but nothing on wankles. The only thing I have done to this rx7 is change the plugs, wires, cap, rotor, and the battery. Everything else is factory. So with that in mind heres is the problem.

About 13 years ago he was coming off the turnpike and when he came to the toll booth the car sputtered, and died. he started it back up but it ran rough, like it had a miss. He tried a few things and then stored it. We moved so he drove it to our new house with the miss, cuz it was only 45 minutes and we followed him. It made it to the house and then we stored it again. So last year I started to mess with it. I tuned it up plugs, wires, ect.... The car will run, it will drive, but at idle it will hesitate, miss, and shut itself off. The plugs look fine, the rotor also good. I think the carb has to be rebuilt, its proly varnished up from old gas, but when the car started to run bad was 13 years ago. I don't know what could be the problem. My Dad doesn't know either, and he is trying not to take it a shop unless we absolutely have to. Any and all help would be appreciated. Thanks
I don't feel like reading that much but what I would do is get your self a can of brake cleaner and with the car running spray the cleaner around the base of the carb, manifold and what not. If the idle rises or evens out you have a vacuum leak.

More than likely you have a MAJOR vacuum leak. I had a similar problem and my leak was coming from a crack hose that went from the intake manifold close to the firewall then the hose went into something else. I can't remember. I do remember plugging it though...
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Old May 18, 2006 | 08:23 AM
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jeff, where in ohio are you? if you're semi close, i can come by and give you a hand.
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