1974 high rpms?
Thread Starter
Heel & Toe
Joined: Jun 2008
Posts: 22
Likes: 0
From: Virginia
1974 high rpms?
Hey guys,
I very new to my 1974 automatic vette and had a couple questions. First my parked rpms when I start cold is always in the 15s. I have read it should be in the 8s though. Is this an indication of something wrong? and if so, anyone have suggestions. Also after I get the car to start (takes a couple tries usually) when I shift it into reverse the rpms drop way down and the engine turns off. It only does this once though. After I get the car started again it usually will go into reverse fine.
I had accredited all of this to an old car being an old car, but the engine turned off (almost like it stalled) on me when I took it out of my neighborhood. So I thought I would get some opinions on this.
Thanks for the help
corvtte74
I very new to my 1974 automatic vette and had a couple questions. First my parked rpms when I start cold is always in the 15s. I have read it should be in the 8s though. Is this an indication of something wrong? and if so, anyone have suggestions. Also after I get the car to start (takes a couple tries usually) when I shift it into reverse the rpms drop way down and the engine turns off. It only does this once though. After I get the car started again it usually will go into reverse fine.
I had accredited all of this to an old car being an old car, but the engine turned off (almost like it stalled) on me when I took it out of my neighborhood. So I thought I would get some opinions on this.
Thanks for the help
corvtte74
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
The fast idle on a 1974 350 automatic is 1600rpm so yours is normal. I set mine to 1200rpm as I think the factory setting is a little high. And yes they do stumble until warmed up. People get used to modern fuel management systems and forget how crude a Q-Jet can be in comparison.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
The fast idle on a 1974 350 automatic is 1600rpm so yours is normal. I set mine to 1200rpm as I think the factory setting is a little high. And yes they do stumble until warmed up. People get used to modern fuel management systems and forget how crude a Q-Jet can be in comparison.
Need to wait a moment or two before it warms up.
The stall is curious though.
A good look at the choke might reveal something.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
Most would set it up to their taste.
Weather is a factor. Hot climates need less choke and a faster
full open.
I like to have a choke set and then come off when I kick it down.
As quick as possible.
Thread Starter
Heel & Toe
Joined: Jun 2008
Posts: 22
Likes: 0
From: Virginia
I like to have a choke set and then come off when I kick it down.
As quick as possible.
As quick as possible.
If I were to post a video of the carb starting cold would people be able to see if something was screwy with it?
Instructor
Joined: Mar 2009
Posts: 187
Likes: 1
From: WA
I have a Holley Street Avenger 670 in my '71 and it died if I put it into gear while still cold. I just did some timing adjustments this weekend and found it was many degrees off in advance. Since you just got yours, look up at the sticky thread in this forum about the long timing post, get yourself a decent adjustable timing gun and time away. you won't regret it! Lots of HP just hiding in these engine that the manufacturer left out in the name of warranty...
Congrats on your new money pit!
Congrats on your new money pit!
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Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
I adjust my choke to open quickly so I can tap the throttle pedal and the
fast idle cam will disengage allowing the throttle to close.
I pick when I want the engine to idle normally.
Sorry i can't explain it better.
Chokes like the one on your car are thermal. there is a coil that expands as it heats up, this pushes a link rod that opens the choke plate.
This is adjustable. Also the fast idle cam has a set screw/like the throttle stop screw. This is were the rpms are controlled when the choke is on.
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
When carb cars were new even women drove them, started right up, didn't die going into reverse, etc. ...
Set the choke to factory specs. & expect as above.
In warm climates we can easily run w/o a choke.
Set the choke to factory specs. & expect as above.
In warm climates we can easily run w/o a choke.
Thread Starter
Heel & Toe
Joined: Jun 2008
Posts: 22
Likes: 0
From: Virginia
Alrighty. Thank you very much for all your help. Im gonna let the engine cool tonight and do some research and then start it up again tomorrow while keeping an eye on the choke and carb. I'll also do some timing research and hopefully this all gets sorted out.
Thanks again for the help, and keep posting if you find more things relevant or any things to watch out for. Im always up for learning more
Thanks again for the help, and keep posting if you find more things relevant or any things to watch out for. Im always up for learning more
