Very high idle
Thread Starter
Burning Brakes
Joined: Dec 2003
Posts: 782
Likes: 0
From: Elizabeth New Jersey
Very high idle
Well it's time to fix everything one at at ime so here goes :
My engine has a very high idle as soon as I fire it, about 2000 rpms , however once it warms up to 185 it drops to normal ( 700-800 ) rpms.
The thing than puzzles me the most though is the sound it makes while it's not warm yet. It sound like it's running on simple air. It makes a turbine sound and not that rich combusting one. However once it warms up it acts just fine.
My engine has a very high idle as soon as I fire it, about 2000 rpms , however once it warms up to 185 it drops to normal ( 700-800 ) rpms.
The thing than puzzles me the most though is the sound it makes while it's not warm yet. It sound like it's running on simple air. It makes a turbine sound and not that rich combusting one. However once it warms up it acts just fine.
Last edited by Corvus; Jan 12, 2005 at 09:14 AM.
Thread Starter
Burning Brakes
Joined: Dec 2003
Posts: 782
Likes: 0
From: Elizabeth New Jersey
Ok I took a pic of the carb :
Now should I turn the pin clockwise or counterclockwise to decrese the idle?
EDIT: By the way I forgot to mention but while the engine warms up the the exaust is very rich.
Now should I turn the pin clockwise or counterclockwise to decrese the idle?
EDIT: By the way I forgot to mention but while the engine warms up the the exaust is very rich.
Tech Contributor
Joined: Aug 1999
Posts: 14,376
Likes: 6,375
From: At my Bar drinking and wrenching in Lafayette Colorado
Just back out your fast idle screw to achieve the idle speed you want. I usually set mine up at about 1000-1200 for initial fast idle - that works fine. But you can set it anywhere you want.
Le Mans Master
Joined: Jan 2003
Posts: 6,575
Likes: 1
From: Tuttle OK
Cruise-In VIII Veteran
Originally Posted by lars
Just back out your fast idle screw to achieve the idle speed you want. I usually set mine up at about 1000-1200 for initial fast idle - that works fine. But you can set it anywhere you want.
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Burning Brakes
Joined: Dec 2002
Posts: 1,069
Likes: 2
From: Sherwood Park AB
No pic here, sorry. The best I can do is go from memory... The fast idle screw is a horizontal screw facing forward on the front of the passenger side of the carb. You would "loosen" the screw to reduce your fast idle speed. You can do this with the car running (on fast idle) and the air cleaner off, just watch out for the fan and belts.
As far as running rich, those would be your idle screws at the front on your carb base. There may be plugs in there if they have never been adjusted.
My 78 Q-jet was running rich, but it was also stumbling under accelleration. I eventually found my float level was way too high, and I set the mixture with a vacuum gauge. I think 1 1/2 turns out on the idle screws is a good starting point.
Read all of Lars' papers on tuning, then read them again. They helped me out a lot.
As far as running rich, those would be your idle screws at the front on your carb base. There may be plugs in there if they have never been adjusted.
My 78 Q-jet was running rich, but it was also stumbling under accelleration. I eventually found my float level was way too high, and I set the mixture with a vacuum gauge. I think 1 1/2 turns out on the idle screws is a good starting point.
Read all of Lars' papers on tuning, then read them again. They helped me out a lot.
Last edited by rexx78; Jan 12, 2005 at 03:25 PM.
