Classic Engine Tech 1967 - 1981 Engine Related

2000 rpm idle (even after warmup)

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Old Oct 2, 2004 | 12:31 AM
  #1  
Tango's Avatar
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Joined: Oct 2004
Posts: 5
From: Everett, Washington
2000 rpm idle (even after warmup)

hey all,

new to the boards and hoping you can help me out. i just got a 1979 z28 with a 4 speed manual. its my first chevy and its been a blast so far, i just have a couple problems i am trying to chase out of it. i tried searching and didn't find anything that answered my question. anyhow, here goes..

i have a rochester quardajet in it. my idle values seem right on when its cold and warming up. i press the gas peddle, choke plate closes, start it up it opens slightly and its right around 1600 for fast idle. after its warmed up, most of the time it will idle way up at 2000 or so. this is after driving around some so i dont think its sticking on fast idle. Then i might park the car and come back out and its behaving itself at 700. Then I start it up a few minutes later and its back up at 2000 again. Gonna check for vacuum leaks maybe? Make sure the carb is torqued down to spec too. it looks like the previous owner removed some of the smog equipment, as i have no air pump and the EFE system had no vacuum hose going to it. There is a sensor on the front of the engine near the water pump that has no hoses to it either. anyone else experienced something like this? hoping you can help and looking forward to talking to you.
Old Oct 4, 2004 | 08:05 PM
  #2  
tom2's Avatar
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Joined: Oct 1998
Posts: 189
From: jackson, ohio, usa
Re: 2000 rpm idle (even after warmup)

Sounds like the choke linkage is sticking where it holds the throttle open. Has a gravity deal that is supposed to pull off the high idle and it does stick sometimes. Check on the side of the carb for this.
Old Oct 11, 2004 | 12:00 AM
  #3  
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Joined: Aug 2004
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From: Warrensburg Missouri
Re: 2000 rpm idle (even after warmup)

Sounds Like A Typical Quadrajunk To Me You Got A Seriouse Vacume Leak Probably Under The Carb Base Ive Seen Alot Of Vehicles Have The Wrong Base Plate Gasket And Cause Them To Suck Air Try Spraying Car&choke Cleaner Around The Base Of The Careurator And Around The Intake To Heads As Well.
Old Oct 17, 2004 | 09:51 AM
  #4  
Black67SS's Avatar
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Joined: Oct 2004
Posts: 12
From: In the desert right now but from live in Florida
Re: 2000 rpm idle (even after warmup)

Sounds like 4 barrel is sticking open alittle bit. Me and my daddy had a dirt track car for years and they Quaderjets are bad about the 4 barrel linkage bining up a little and causing the 4 barrel to stay open. You can one tap on the side of the linkage with a screwdriver head lightly. 2 try WD-40. Other wise don't know what to tell you.
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