Q-jet fast idel
Thread Starter
Racer
Joined: Sep 2010
Posts: 430
Likes: 0
From: SIGONELLA Sicily
Q-jet fast idel
Over the last few months I noticed when my 72 was warm if I hit the gas before I started it I would have to get out and manualy open the butterfly. I know my choke is all buggered up and plan to rebuild. I am stationed in Italy and my Corvette is my daily driver.
This morning on the way to work I let off the gas and the engine kept reving. After I got on base I looked under the hood and the butterflys were stuck open. I shut it off and after it got done sputtering and finaly died I hit the gas and the butterflys shut fine. I started it back up and it did the same thing! I prefer to keep a Q-jet on the car so please dont tell me to change it. I know I need a rebuild and will order the parts but It will take a while to get them. I was wondering if anyone has any suggestions on how to fix this problem as I am new to Q-jets I have a copy of LARS rebuild papers at home but no way to get there without running way TOO high RPMs on the way home.
Thank you in advance for your sugestions.
P.S. yes I used the search and found lots of Q-jet stuff just not this perticular problem.
cm2dinger
This morning on the way to work I let off the gas and the engine kept reving. After I got on base I looked under the hood and the butterflys were stuck open. I shut it off and after it got done sputtering and finaly died I hit the gas and the butterflys shut fine. I started it back up and it did the same thing! I prefer to keep a Q-jet on the car so please dont tell me to change it. I know I need a rebuild and will order the parts but It will take a while to get them. I was wondering if anyone has any suggestions on how to fix this problem as I am new to Q-jets I have a copy of LARS rebuild papers at home but no way to get there without running way TOO high RPMs on the way home.
Thank you in advance for your sugestions.
P.S. yes I used the search and found lots of Q-jet stuff just not this perticular problem.
cm2dinger
Thread Starter
Racer
Joined: Sep 2010
Posts: 430
Likes: 0
From: SIGONELLA Sicily
I am not completly sure myself. Sorry I dont have more info at the moment but in about 4 hours or so I am gonna be trying my best to fix it LOL
I do know its not in the throttle cable
I do know its not in the throttle cable
Racer
Joined: Aug 2000
Posts: 434
Likes: 3
From: Cleveland Ohio
Check the linkage to make sure the springs are closing the throttle blades. There should be two connected were the cable from the gas pedal connects to the carb. Also disconnect the cable and see if it moves freely along with turning the throttle by hand. Sounds like something is sticking or you are missing/broken the return springs. 
Melting Slicks
Joined: Mar 2008
Posts: 2,023
Likes: 6
From: Austin Tx
I definately sounds like your choke is very buggered up. When your car is cold, 1 press of the gas pedal should close the butterfly, and put on the fast idle. When you start the car, the butterfly should open a bit, and idle fast. Pressing the gas pedal again should take the carb off the fast idle.
Email Lars @ V8FastCars@msn.com and ask him for his q-jet choke setup paper. It's very straight forward, and you'll learn a lot about how the choke, and your q-jet work.
Lars prefers for people to ask him for the current version of his papers, so they get any updates he has made.
Email Lars @ V8FastCars@msn.com and ask him for his q-jet choke setup paper. It's very straight forward, and you'll learn a lot about how the choke, and your q-jet work.
Lars prefers for people to ask him for the current version of his papers, so they get any updates he has made.
Race Director
Joined: May 2006
Posts: 18,695
Likes: 2,572
You stated when warm the butterflys were open. If you are talking about the choke butterfly on the primary side of the carburetor they should be open when warm. If you are talking about the air valve on the secondary side of the carburetor they should be closed. If you do mean the secondary air valve was open, you either have a binding valve or the tension spring is broken. If you mean the primary throttle blades try spraying the choke linkage with carburetor cleaner.
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Thread Starter
Racer
Joined: Sep 2010
Posts: 430
Likes: 0
From: SIGONELLA Sicily
MELWFF you were right I just cleaned the linkage and did a slight adjustment on the A/F mix and I am now running again!
still need a rebuild and I think I'm gonna go ahead and replace the springs while I am at it I have no idea how old they are but they dont look new...
still need a rebuild and I think I'm gonna go ahead and replace the springs while I am at it I have no idea how old they are but they dont look new...
