summertime...new carburation?
Thread Starter
Burning Brakes
Joined: Sep 2008
Posts: 753
Likes: 0
summertime...new carburation?
I took a while to get a good carburation a couple of months ago...idle mix and jetting , but due to hot wheater , do I need to retune?
the idle speed has passed from 1000rpm or less to 1100 or slightly more.
I haven't check the plugs yet but I'm sure that they are not so clean as before.
advises are welcome.
-take the idle back to 1000rpm with the idle mix screws?
-rejet the carb ? Holley DP 800 with 72 prim jets and 78 sec jets now
the idle speed has passed from 1000rpm or less to 1100 or slightly more.
I haven't check the plugs yet but I'm sure that they are not so clean as before.
advises are welcome.
-take the idle back to 1000rpm with the idle mix screws?
-rejet the carb ? Holley DP 800 with 72 prim jets and 78 sec jets now
Racer
Joined: Jan 2008
Posts: 338
Likes: 0
your carburator is tuned to the ambient conditions (air density and temperature) that were present when you set it. I guess the real question is, were the conditions when you tuned it significantly different than now? (ie: 40 deg F to 110 deg F)
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
You might need to adjust the choke and/or fast idle speed adjustment for better "start up" behavior...but there shouldn't be any need to re-jet unless you have some other system problem [i.e., vacuum leak, etc.].
Safety Car
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
I took a while to get a good carburation a couple of months ago...idle mix and jetting , but due to hot wheater , do I need to retune?
the idle speed has passed from 1000rpm or less to 1100 or slightly more.
I haven't check the plugs yet but I'm sure that they are not so clean as before.
advises are welcome.
-take the idle back to 1000rpm with the idle mix screws?
-rejet the carb ? Holley DP 800 with 72 prim jets and 78 sec jets now
the idle speed has passed from 1000rpm or less to 1100 or slightly more.
I haven't check the plugs yet but I'm sure that they are not so clean as before.
advises are welcome.
-take the idle back to 1000rpm with the idle mix screws?
-rejet the carb ? Holley DP 800 with 72 prim jets and 78 sec jets now
I only experience this with Holley carbs (?), Edelbrock carbs hold their tune and don't seem to change.
Thread Starter
Burning Brakes
Joined: Sep 2008
Posts: 753
Likes: 0
OK
so to readjust the idle speed ,not the idle mix ( 2 screws)
I supposed that being the air hotter in summer is also less dense , so the A/F mix tends to be rich. the theory should be this...
I'll do a test with a vacuum gage connected to the intake and see if the mix requires to be leaner or not. if not , I'll simply readjust the idle speed
thanks
so to readjust the idle speed ,not the idle mix ( 2 screws)
I supposed that being the air hotter in summer is also less dense , so the A/F mix tends to be rich. the theory should be this...
I'll do a test with a vacuum gage connected to the intake and see if the mix requires to be leaner or not. if not , I'll simply readjust the idle speed
thanks
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski