C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Carb help

Thread Tools
 
Search this Thread
 
Old Jul 2, 2010 | 03:01 PM
  #1  
68sting's Avatar
68sting
Thread Starter
Instructor
10 Year Member
 
Joined: Oct 2008
Posts: 154
Likes: 5
From: Colorado Springs
Default Carb help-vapor lock or something

I just got my car back on the road today. I cruised around for awhile (no hood) and stopped at a fiends house for a few minutes. When I started the car up all was fine until I hit the accelerator and gas came pouring out of the front vent tube on the carb flooding it. I started it back up and gave it some gas and raw gas shoots out of both vent tubes and onto the windshield. Any ideas what this is? It ran fine after this initial incident.

Last edited by 68sting; Jul 3, 2010 at 06:50 PM.
Reply
Old Jul 2, 2010 | 03:39 PM
  #2  
Paul Ruggeri's Avatar
0Paul Ruggeri
Former Vendor
 
Joined: Nov 2006
Posts: 2,482
Likes: 3
From: Carmichael ca
Default

Sounds like something has gotten between the needle and seat and is holding it open. Sometimes all it takes ia a little bit of dirt. That or the float is stuck.
Reply
Old Jul 2, 2010 | 06:23 PM
  #3  
68sting's Avatar
68sting
Thread Starter
Instructor
10 Year Member
 
Joined: Oct 2008
Posts: 154
Likes: 5
From: Colorado Springs
Default

I checked the float level when I got back home and they were fine at that point. Should I just drive it a little more and see if the crud gets out or do you recommend I take the bowls off and have a look. Thanks for the help.
Reply
Old Jul 2, 2010 | 07:05 PM
  #4  
Paul Ruggeri's Avatar
0Paul Ruggeri
Former Vendor
 
Joined: Nov 2006
Posts: 2,482
Likes: 3
From: Carmichael ca
Default

There is a risk of an underhood fire, so I would check it out right away.
Reply
Old Jul 2, 2010 | 07:21 PM
  #5  
sjr1971's Avatar
sjr1971
Racer
15 Year Member
 
Joined: Dec 2003
Posts: 275
Likes: 6
From: NY
Default

Originally Posted by 68sting
I just got my car back on the road today. I cruised around for awhile (no hood) and stopped at a fiends house for a few minutes. When I started the car up all was fine until I hit the accelerator and gas came pouring out of the front vent tube on the carb flooding it. I started it back up and gave it some gas and raw gas shoots out of both vent tubes and onto the windshield. Any ideas what this is? It ran fine after this initial incident.
You have a problem with your carb. A Rochester ? If so, your air valve should be closed at idle. When the engine loses vacuum at high RPM ,that releases the air valve above the secondary butterfly valve; it also pulls up the secondary rods that supply gas through the secondary jets to to the secondary's butterfly valve
Reply
Old Jul 2, 2010 | 07:27 PM
  #6  
68sting's Avatar
68sting
Thread Starter
Instructor
10 Year Member
 
Joined: Oct 2008
Posts: 154
Likes: 5
From: Colorado Springs
Default

Its a 750 holley from the Carb Shop.
Reply
Old Jul 2, 2010 | 09:52 PM
  #7  
Timsride's Avatar
Timsride
Burning Brakes
 
Joined: May 2008
Posts: 860
Likes: 0
From: Stratford Ontario
Default

You have to check the needle and seat, You probably have something stuck in there. It is probably too big to go through on its own. Are You running an external filter?
Reply
Old Jul 3, 2010 | 12:16 AM
  #8  
68sting's Avatar
68sting
Thread Starter
Instructor
10 Year Member
 
Joined: Oct 2008
Posts: 154
Likes: 5
From: Colorado Springs
Default

I am but the carb has been of for a while now.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-1

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-2

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-3

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-4

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-5

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-6

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-7

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-8

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-9

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
Old Jul 3, 2010 | 05:41 PM
  #9  
68sting's Avatar
68sting
Thread Starter
Instructor
10 Year Member
 
Joined: Oct 2008
Posts: 154
Likes: 5
From: Colorado Springs
Default

I put the hood on today and went for a spin. I'm getting an old problem that I never fixed. I'm having a vapor lock issue I believe. When it does this the carb appears to boil over. I run a Holly blue pump thats mounted in the back. Next up is the mechanical filter and then the regulator that has a pressure gage. My pressure will drop to 0 and you can hear the pump surging. It will stay at zero long after the car has been sitting. I switched pumps and regulators but same problem. Any ideas on this?

Reply

Get notified of new replies

To Carb help





All times are GMT -4. The time now is 01:13 PM.

story-0
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-1
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-2
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-3
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-4
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-5
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-6
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-7
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-8
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-9
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE