Edelborck Carb Help Needed
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,414
Likes: 1
From: NC
Edelborck Carb Help Needed
I have installed a 1406 Edelbrock carb on my 350 and have it running pretty well now. I installed a O2 sensor and a Fuel/O2 ratio gage and have the idle, cruse and WOT all set.
The only problem I have is the hesitation at quick throttle. It seems to be a lean mixture issue. I have a Accelerator nozzle kit on order and should get it today.
Can anyone advise me as to which nozzle to use? Just trying to save some time and figure someone else has all ready gone thru this.
TIA
Bill
The only problem I have is the hesitation at quick throttle. It seems to be a lean mixture issue. I have a Accelerator nozzle kit on order and should get it today.
Can anyone advise me as to which nozzle to use? Just trying to save some time and figure someone else has all ready gone thru this.
TIA
Bill
Pro
Joined: Sep 2006
Posts: 551
Likes: 2
From: Clovis CA
I had the Edelbrock 1813,800cfm, same hesitation,changed the pump,added dual fuel feed, adjusted, still couldn't fix it. So I put on a Holley and no more problem....Maybe I don't understand the Edelbrock,I don't know...
Intermediate
Joined: Oct 2006
Posts: 27
Likes: 0
From: Virginia
carb hesitation
Edelbrock sells a calibration kit for your 1406 carb through summit, part number EDL-1487 for 35.00. You might want to ask them if they sell an accelerator pump cam kit. Most of the time your accelerator pump isnt squirting fuel long enough and your engine will lean out and you feel a bog/hesitation, sucks. Ensure you check that your vacumn advance is working before spending any more money on carb parts. Holley carbs do offer more tunability and faster parts swapping ability for the weekend garage parties... Good luck, Aaron
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,414
Likes: 1
From: NC
Edelbrock sells a calibration kit for your 1406 carb through summit, part number EDL-1487 for 35.00. You might want to ask them if they sell an accelerator pump cam kit. Most of the time your accelerator pump isnt squirting fuel long enough and your engine will lean out and you feel a bog/hesitation, sucks. Ensure you check that your vacumn advance is working before spending any more money on carb parts. Holley carbs do offer more tunability and faster parts swapping ability for the weekend garage parties... Good luck, Aaron
I already purchased the calibration kit. I used the fuel/O2 gage to set the idle mixture. Changed the primary rods to get the correct ratio for cruse and no change was needed for WOT.
Only issue is the stumbling on acceleration. I have the linkage set to the hole closest to the fulcrum.
Bill
Burning Brakes
Joined: Nov 2003
Posts: 990
Likes: 0
From: North Texas
Is the stumble only from inital acceleration?
I think you actually need to move the accelerator pump in the opposite direction.
It could also be your "Step-up" springs.
What values are you using to set your A/F for Idle, Crusing, and WOT?
Let me know.
I think you actually need to move the accelerator pump in the opposite direction.
It could also be your "Step-up" springs.
What values are you using to set your A/F for Idle, Crusing, and WOT?
Let me know.
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,414
Likes: 1
From: NC
If I move the linkage away from the fulcrum then the travel will be less but will have more force. Think of it as a seesaw
The values I am adjusting to is 13 to 14 : 1.
Bill
Burning Brakes
Joined: Nov 2003
Posts: 990
Likes: 0
From: North Texas
Bill,
What kind of O2 sensor are you using? If it's a Heated Wide-band you should be able to tell if your rich or lean on inital acceleration.
If I remember correctly, you want the shorter travel because that has a larger "squirt". If your lean, then you need the larger "squirt" but if your rich, it needs to move the other direction which would be a "bog".
How much vacuum do you have at idle?
I noticed on my EPS 800 that I had to stay closer to 13 than 14 A/F at idle.
So, I would shoot for an idle around 13, about 14 for the cruise circuit and you need to be down around 12.5 for WOT. I'm still working on my cruise circuit. I had to order some new rods to get the correct combination but I haven't had a chance to test.
I would also suggest for now to go with the lightest springs (Blue) until you resolve the stumble. Then start adjusting upwards until you have a stumble and then go back one spring.
What's the current configuration - Jets and Rods?
Tim
What kind of O2 sensor are you using? If it's a Heated Wide-band you should be able to tell if your rich or lean on inital acceleration.
If I remember correctly, you want the shorter travel because that has a larger "squirt". If your lean, then you need the larger "squirt" but if your rich, it needs to move the other direction which would be a "bog".
How much vacuum do you have at idle?
I noticed on my EPS 800 that I had to stay closer to 13 than 14 A/F at idle.
So, I would shoot for an idle around 13, about 14 for the cruise circuit and you need to be down around 12.5 for WOT. I'm still working on my cruise circuit. I had to order some new rods to get the correct combination but I haven't had a chance to test.
I would also suggest for now to go with the lightest springs (Blue) until you resolve the stumble. Then start adjusting upwards until you have a stumble and then go back one spring.
What's the current configuration - Jets and Rods?
Tim
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,414
Likes: 1
From: NC
Bill,
What kind of O2 sensor are you using? If it's a Heated Wide-band you should be able to tell if your rich or lean on inital acceleration.
If I remember correctly, you want the shorter travel because that has a larger "squirt". If your lean, then you need the larger "squirt" but if your rich, it needs to move the other direction which would be a "bog".
How much vacuum do you have at idle?
I noticed on my EPS 800 that I had to stay closer to 13 than 14 A/F at idle.
So, I would shoot for an idle around 13, about 14 for the cruise circuit and you need to be down around 12.5 for WOT. I'm still working on my cruise circuit. I had to order some new rods to get the correct combination but I haven't had a chance to test.
I would also suggest for now to go with the lightest springs (Blue) until you resolve the stumble. Then start adjusting upwards until you have a stumble and then go back one spring.
What's the current configuration - Jets and Rods?
Tim
What kind of O2 sensor are you using? If it's a Heated Wide-band you should be able to tell if your rich or lean on inital acceleration.
If I remember correctly, you want the shorter travel because that has a larger "squirt". If your lean, then you need the larger "squirt" but if your rich, it needs to move the other direction which would be a "bog".
How much vacuum do you have at idle?
I noticed on my EPS 800 that I had to stay closer to 13 than 14 A/F at idle.
So, I would shoot for an idle around 13, about 14 for the cruise circuit and you need to be down around 12.5 for WOT. I'm still working on my cruise circuit. I had to order some new rods to get the correct combination but I haven't had a chance to test.
I would also suggest for now to go with the lightest springs (Blue) until you resolve the stumble. Then start adjusting upwards until you have a stumble and then go back one spring.
What's the current configuration - Jets and Rods?
Tim
Thanks Tim,
I am using Edelbrock's Sensor and gage kit, don't know the part number off hand.
I have about 14 to 16 hg at manifold at idle.
I changed the stock primary rod to the riches rod in the kit because at cruse it was so lean it did not light the 15:1 light (this is a led gage read from right 15 to left 11) unless I just barley let off the accelerator. As soon as I applied any pressure to the peddle all lights would go off. I am getting a good 12 at WOT
And 14 at idle.
I was thinking does the accelerator plunger regulated but spring pressure? If this is the case then it makes sense to put the larger diameter nozzle from the kit.
Can you explain how the spings function?
Bill
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
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
Burning Brakes
Joined: Nov 2003
Posts: 990
Likes: 0
From: North Texas
Bill,
I'm not sure I understand your question.
The "Step-up" springs (3" Hg (blue), 4" Hg (yellow), 5" Hg (orange), 7" Hg (pink) and 8" Hg (plain) springs) are used to tune the rate of enrichment. Basically how fast the metering rods react to changes.
The Accelerator Plunger spring to the best of my knowledge is not a factor. It has more to do with the volume of the plunger and size of the nozzle.
If you have 14-16", you should be able to move more towards the orange or pink spring in your final configuration.
Tim
I'm not sure I understand your question.
The "Step-up" springs (3" Hg (blue), 4" Hg (yellow), 5" Hg (orange), 7" Hg (pink) and 8" Hg (plain) springs) are used to tune the rate of enrichment. Basically how fast the metering rods react to changes.
The Accelerator Plunger spring to the best of my knowledge is not a factor. It has more to do with the volume of the plunger and size of the nozzle.
If you have 14-16", you should be able to move more towards the orange or pink spring in your final configuration.
Tim
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,414
Likes: 1
From: NC
Bill,
I'm not sure I understand your question.
The "Step-up" springs (3" Hg (blue), 4" Hg (yellow), 5" Hg (orange), 7" Hg (pink) and 8" Hg (plain) springs) are used to tune the rate of enrichment. Basically how fast the metering rods react to changes.
The Accelerator Plunger spring to the best of my knowledge is not a factor. It has more to do with the volume of the plunger and size of the nozzle.
If you have 14-16", you should be able to move more towards the orange or pink spring in your final configuration.
Tim
I'm not sure I understand your question.
The "Step-up" springs (3" Hg (blue), 4" Hg (yellow), 5" Hg (orange), 7" Hg (pink) and 8" Hg (plain) springs) are used to tune the rate of enrichment. Basically how fast the metering rods react to changes.
The Accelerator Plunger spring to the best of my knowledge is not a factor. It has more to do with the volume of the plunger and size of the nozzle.
If you have 14-16", you should be able to move more towards the orange or pink spring in your final configuration.
Tim
Bill
Racer
Joined: Jan 2005
Posts: 499
Likes: 0
From: Enfield CT
I have installed a 1406 Edelbrock carb on my 350 and have it running pretty well now. I installed a O2 sensor and a Fuel/O2 ratio gage and have the idle, cruse and WOT all set.
The only problem I have is the hesitation at quick throttle. It seems to be a lean mixture issue. I have a Accelerator nozzle kit on order and should get it today.
Can anyone advise me as to which nozzle to use? Just trying to save some time and figure someone else has all ready gone thru this.
TIA
Bill
The only problem I have is the hesitation at quick throttle. It seems to be a lean mixture issue. I have a Accelerator nozzle kit on order and should get it today.
Can anyone advise me as to which nozzle to use? Just trying to save some time and figure someone else has all ready gone thru this.
TIA
Bill
Advanced
Joined: Apr 2006
Posts: 87
Likes: 0
From: Finly IN
Carb Tuning
Your topic couldn't have come at a better time. I have a newly installed Edelbrock 1406, that I am trying to fix the "stumble or hesitation." Don't forget the Edelbrock web site for tuning tips as well. Sounds like the same issues. thanks for posting the topic.
Instructor
Joined: Sep 2006
Posts: 192
Likes: 0
From: Fort Lauderdale FL
If you haven't already download the Edelbrock Carb Owners Manual from their web site and it will take you through all of the spring set-up by color etc. Very useful
Also on the accelerator pump are you should have 3 holes for mounting the linkage. The one closest to the carb and also the highest hole is for richer than baseline (the center hole) and leaner the last, bottom hole furthest away from the carb body.
In you case it seems that you want to set it to the first hole, richer, and see if that takes care of the stumble.
Good luck
Also on the accelerator pump are you should have 3 holes for mounting the linkage. The one closest to the carb and also the highest hole is for richer than baseline (the center hole) and leaner the last, bottom hole furthest away from the carb body.
In you case it seems that you want to set it to the first hole, richer, and see if that takes care of the stumble.
Good luck
Racer
Joined: Jan 2005
Posts: 499
Likes: 0
From: Enfield CT
Oles carberutor out of CA.sells a accelerator pump with a more active spring that is supposed to help with a hesiation.A guy named Henry is on this forum.I think that different sized accelerator nozzles would correct your hesiation.
1406, 1813, 350, acceleration, adjust, carberutor, carburetor, choke, edelbrock, hesitation, idle, stumbles, summit, v8, wot
