Carter competition series carb problem

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Dart360Custom

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I have a bad stumble a little off idle. The car starts move, then the stumble, then keep pushing the trottle and it goes past the stumble and really takes off.
I dont need to accelerate hard from a stop to make it happen. It happens even if i'm accelerating slowly.


i believe the carb is a 750 cfm, the pump adjustment is set in the hole farthest away from the carb i believe it is a pump shot issue. any ideas?
 
Do you have a aftermarket cam? My first guess is to try different metering rod springs, if you buy a tuning kit for it, those should come with. They are different strengths and will pull up the metering rods differently depending on the vacuum your motor makes. Thats what i'd first look at.
 
Are you certain the accel pump is giving a good shot ? Maybe it needs to be rebuilt ? For the fastest pump shot you want to move the linkage to the hole nearest the pivot on the pump arm.
 
I had the exact same problem on my T-Quad. It would stumble right off idle, no matter how hot or cold the engine was. (If you don't have a choke and the engine is cold, you will get the same symptoms).

At first I thought that i might of been just that... the choke. I even went so far as to fashion a metal plate to partially cover the primary choke horn so to have a permanent choke. That solved the symptom, but not the problem. Ultimately, I found out the real problem was a vacuum leak under the base of the carb. Needed the correct gasket, not the one I was using for the Q-Jet that the T-Quad replaced.

I found the problem by spraying the areas that are prone to vacuum leaks(carb base, intake to head gasket area) with Ether(starting fluid). It was pretty evident I had a leak under the carb when the engine revved up after a quick shot of Ether....

Hope this helps...
 
GoodysGotaCuda said:
Do you have a aftermarket cam? My first guess is to try different metering rod springs, if you buy a tuning kit for it, those should come with. They are different strengths and will pull up the metering rods differently depending on the vacuum your motor makes. Thats what i'd first look at.
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yeah, im pretty sure its a purple shaft it was in the car when i bought it. im slowly trying to get the car running right. Seems like removing the 700 double pumper was a good move also in both gas milage and power areas. The motor makes about 12" of vaccume.
 
66dartgt said:
Are you certain the accel pump is giving a good shot ? Maybe it needs to be rebuilt ? For the fastest pump shot you want to move the linkage to the hole nearest the pivot on the pump arm.
Click to expand...


Yeah,as soon as the arm move it shoots gas, What it really acts like is a holley with a loose pump arm. Maybe it needs a larger squirter?
 
Dart360Custom said:
the pump adjustment is set in the hole farthest away from the carb i believe it is a pump shot issue. any ideas?
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And you are correct. The pump arm should be in the whole closest to the carb for a quicker and larger pump shot. Follow the instructions closely. Edelbrocks will do as well.
 
well carter comp.series carbs are the same thing as edlebrocks eddy bought out carter
but those carbs are old so it is probably in need of a good rebuild dead spots in a carb will end up with you in a ditch
 
If messing with the pump doesnt help, then get a set of the springs for the metering rod dashpots. Try putting in a set of stiffer springs than what are in there now. What this will do is shorten the metering rods response time to off idle and throttle tip in, it will enrichen the mixture faster.

If that helps but doesnt fix it, then you may need a different set of metering rods as well, look at your metering rods that are in the carb, there will be tiny numbers coded on the side of the rod towards the J end of the rods. THis code number will tell you what the sizes are of the various steps on the rod. You can also measure these - more or less by using a caliper. Then look for some rods that have smaller sizes on the various steps and try them out. Very slight changes will probably be all thats needed.

Eventually you may need to change out the jets to get where you need to go, but start with the springs - then rods - then jets.

In order to really understand what you are doing with these things - I like to calculate the changes you make whenever you swap parts, you can calculate the change by calculating the area of the various rod steps minus the area of the jet and compare various combinations of rods and jets to get a more precise idea of what you are really doing by changing this stuff around. (I know I am being anal, but it's the science of doing this that I like). It also leads you to the correct decisions faster as well rather than guessing.
 
rumblefish360 said:
And you are correct. The pump arm should be in the whole closest to the carb for a quicker and larger pump shot. Follow the instructions closely. Edelbrocks will do as well.
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i moved it to the hole closest to the carb and it is a little better, i may try pull the lid off and clean the squirter out and have a look around inside. I believe it may just be a hair too small
 
1qwikScamp said:
well carter comp.series carbs are the same thing as edlebrocks eddy bought out carter
but those carbs are old so it is probably in need of a good rebuild dead spots in a carb will end up with you in a ditch
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carb runs good otherwise just not enough of a pump shot. I hate to sink 40 bucks in a kit then 45 bucks in a tuning kit and it not repair the issue.
 
Edelbrock more likey sells the squirter cluster. I got mine from Carter years ago. They had 2 sizes larger and one smaller. Go there first. Remember to readjust the arm for proper travel.
 
Dart360Custom said:
carb runs good otherwise just not enough of a pump shot. I hate to sink 40 bucks in a kit then 45 bucks in a tuning kit and it not repair the issue.
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*disclaimer, just in my opinion*

If your only complaint is your off-idle hesitation then i'd put money that just a rebuild would do you no good, its quite a common issue with motors with hotter than stock cams. There was a post on here not a week ago with the same issue and the springs was the fix...If you dont want to spend $45 on the tuning kit, then just buy the spring assortment. I put that up there in case you wanted different jets/rods if your a/f ratio needed adjustment...Moving the pump shot to a more aggressive shot will probably seem better because it is helping band-aid the slight hesitation due to too weak of metering rod springs by giving it slightly more fuel. Your metering rods are probably down/lean at idle and as soon as you step on it will be lean until those springs bring the rods out of the jets and give it more fuel. Stiffer springs will bring the rods up like they are supposed to and probably cure your issue. Pump shot is more orientated for start-up, and when you really mash the pedal off the line. Not much for just leaving a stop sign or what have you...

just my 2cents..

http://store.summitracing.com/partd...925239+4294839063+4294848605+115&autoview=sku

$6 for just the springs. I bet your local advanced, pepboys, or checker can get it as well..
 
GoodysGotaCuda said:
*disclaimer, just in my opinion*

If your only complaint is your off-idle hesitation then i'd put money that just a rebuild would do you no good, its quite a common issue with motors with hotter than stock cams. There was a post on here not a week ago with the same issue and the springs was the fix...If you dont want to spend $45 on the tuning kit, then just buy the spring assortment. I put that up there in case you wanted different jets/rods if your a/f ratio needed adjustment...Moving the pump shot to a more aggressive shot will probably seem better because it is helping band-aid the slight hesitation due to too weak of metering rod springs by giving it slightly more fuel. Your metering rods are probably down/lean at idle and as soon as you step on it will be lean until those springs bring the rods out of the jets and give it more fuel. Stiffer springs will bring the rods up like they are supposed to and probably cure your issue. Pump shot is more orientated for start-up, and when you really mash the pedal off the line. Not much for just leaving a stop sign or what have you...

just my 2cents..

http://store.summitracing.com/partd...925239+4294839063+4294848605+115&autoview=sku

$6 for just the springs. I bet your local advanced, pepboys, or checker can get it as well..
Click to expand...


I have a buddy thats going to bring me his tuning kit will try swapping the springs and see what happens.



It seems more predominant when it is cold (less the 140* on the gauge) and you barely touch the gas to move from a stop(like an old lady would drive)if you accelerate normal it does alright.
 
rumblefish360 said:
Edelbrock more likey sells the squirter cluster. I got mine from Carter years ago. They had 2 sizes larger and one smaller. Go there first. Remember to readjust the arm for proper travel.
Click to expand...

Ill check into that also thanks man. if i cant find one ill break out the tiny drill bits :angel9:
 
Don't know if this will help but i had the exact same problem with my 750 eddy performer carb,thought it was too lean at first ended up it was to rich and just needed stiffer springs in it.
 
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