455 with the edlebrock performer intake and a brand new 1411 750 carb with electric choke. I just put the new carb on and I’m having an issue. The issue is when im sitting idleing in park and punch the throttle real hard the car like stumbles / shutters for a second then revs out . But if you gradually apply the throttle it revs out smoothly as it should . Car does not do this when driving and you stomp it doing 40 . I’m very confused as to why this is happening. I’ve been told by a few people that it’s just the nature of the beast but it did not do this when the 600cfm 1406 was on the car . Any input would be appreciated.

 

Check the accelerator pump setting. You may also need to move the rod to the lowest hole to allow a larger volume of fuel. The pump should put out fuel as soon as the linkage moves. Also timing can cause this issue.

 

I had the same problem on my Edelbrock carbed 350 almost 20 years ago. I threw the carb away.
But a better path would be to buy a wideband and see what it’s doing when it does this. A stumble can be from an overly rich condition the same way it can be from a lean one.

 

I did move it to the center hole. This did help but not completely . The top hole closest to the carb was the worst and the bottom hole was not any better than the center.

 

You need to buy the Edelbrock spring/jet/rod kit. No carb will run 100% out of the box.... don't expect yours to.
Get the kit with a larger assortment of parts...Jegs Summet and Ebrock will have it.
ollow Edelbrocks fuel curve maps. It sounds harder than it is. Call them and ask them to send the tuning guide electronically.
This carb is VERY tunable and friendly carb and the parts are changed without disassembly.

Call them and ask which kit applies to the 1411

Example only:
https://www.summitracing.com/parts/e...8aAs7eEALw_wcB

 

And none of that means anything unless you know which way you’re going. BUY A WIDEBAND AND DO IT THE RIGHT WAY.

 

But with an analog car, I've been doing it this way for many years for street. Track yes wide band AND dyno.

 

What is an analog car? Never heard that before.

 

Did you change anything other than the carburetor ?

 

I put the edlebrock rubber/ insulated spacer on

 

I think the first thing I would do is put the old carburetor back on and see if the problem goes away. That way you know for certain the new carb will need some tuning. It sounds like maybe the secondary air valve is opening too quickly. You could try adjusting that a little at a time and see what happens.

 

I'm not a know it all. I am a good trouble shooter. I do know carbs.
I'm simply trying to pass along some seasoned experience to prevent you from loosing your hair and faith in this carb. Its a great carb when properly dialed in.

The E-Brock tuning guide describes all of this and how to fix it. Get the rod, jet, spring kit. It could be as simple as choosing the correct springs. It fixed this same problem I had with a 1900 series AVS.

A systematic approach must be employed for carb tuning. You need to always be able to get back to where you started before going down a second path.
Pulling too many levers at once will do nothing but send you down a rabbit hole and you will be quickly disgusted with the carb.

I recommend not touching anything until you read the tuning guide.

 

I agree, follow a tuning guide to tell you what order to make changes. Usually idle and main jets are first (steady running state), then the guide should tell you what to do next. The order is critical.

 

A while back, anytime someone's Olds ran like ***** it had one common denominator, guess what it was? A wide band is great, a couple of screw turns can make a big difference for tune.

 

Hmmm, not if you had a wideband on it to tell you where you are at any given point.
And you never answered my question, what is an analog car? Again never heard that term before.
Thank you.

 

Perhaps he meant an analog carb. So basically a mechanical carb as opposed to computer controlled or efi system.

I totally agree with you. If you change a carb you absolutely should be using a wideband to set it up correctly. Years ago pre wideband a/f meters and without access to a dyno, we would do it over weeks of test drives with a stopwatch, monitoring gas mileage etc, and seat of the pants. That would provide a serviceable setup, but nowhere near optimal. With a wideband and knowledge you can do it much more quickly and get a much more accurate, powerful, and fuel efficient setup.

 

Here's a well reviewed O2 sensor. The price is competitive too. I spent just as much on both an AutoMeter coolant temperature sensor and a pyrometer for my 86 Ford F250. I don't have an O2 sensor for tuning, but this would be the one I'd get for my 71 Oldsmobile. Either that or just pay a performance shop to tune it with a 5 gas analyzer and a dyno.

https://www.summitracing.com/parts/atm-3370