84 Z28 HO 305, stock, other than Edelbrock performer intake and Edelbrock 750cfm manual choke carb. The carb, I've been told many times, is too large, and it is likely the reason why at more than 70mph, or when pushing hard off the line, the car seems starved for fuel and stars to putter and stutter. I have to pull over and let it settle down for a few minutes before going again.

So I'm thinking about a 650cfm AVS2, but unsure about manual vs electric choke. I live in central NC, where it does not get too cold. This is also a convertible with no top right now, so only a sunny day for the time being. With the current carb and manual choke, I never installed anything on it so can't say it ever got used. But I also have no idea where a wire for an electric choke would be.

This car is strictly a street car, no roof (someday I will get a new top on it), no roll cage, no racing. Just a nice car to enjoy, and sometimes punch it when coming onto the highway, and stable enough to take to the mountains or the beach.

Thanks!

 

The 650 CFM Edelbrock AVS2 is a better size for you 5.0L engine and the AVS2 is a much better street carb than the Performer. This assumes your L69 5.0L H.O. engine is close to stock and not built out the azz.

Their is a calibration difference between the electric choke version and the manual choke version. The manual choke version is calibrated a little richer. I'd get the electric choke version. It's a simple hook up. It comes with instructions and there lots of good videos on YouTube.

Muscle Car Solutions - YouTube

There are drop base air cleaner clearance considerations too. Your air cleaner base might not clear the electric choke version of the carb.

Carbs aren't a bolt on and forget about it thing. They must be calibrated to suit your engine and car. Edelbrock has an excellent tuning and calibration guide and calibration kits.

 

If it's starving for fuel I think you may need to look at how the carb is tuned. That does sound like a lot of carb for an otherwise stock motor though, it should be dumping gas with minimal effort.

That being said, I've had a manual choke forever, no issues hopping in it and going, even when cold. If it's 40 or below the car prefers to sit and I'll manually give it a "high idle" (aka just hold the pedal a little) for a minute or two. I don't even use the manual choke.

 

No.

The carb may well be too large, butt that's not what's causing this.

Most likely it's a fuel delivery issue. Has nothing to do with carb CFM capacity. ANY carb you put on there would almost certainly do the same thing. Gotta fix that FIRST. I'd recommend checking the gas tank for crusties built up in the fuel pickup and lines, replacing the fuel pump (a new stock one with return will be just fine, making sure the pump drive rod floats freely in its passage, maybe even getting a lightweight drive rod. And as mentioned, TUNING: no carb is ever going to be "perfect" for any engine right out of the box. Best you can hope for is that it's close enough to run. Though I'm not a fan of Edelbrock's carbs, their instructions for tuning them are pretty thorough and easy to follow.

Along the right valve cover, in the harness with the alternator wiring; it's light blue. Your existing carb will probably need a choke once you get it dialed in properly. Reason being, it won't be PIG RICH all the time at idle, and thus will need the added enrichment from a choke when it's cold.
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Sofa is 100% right about this. I was thinking the same thing when replying and was going to mention it but got a phone call and had company coming over so posted what I had with the intention of editing my reply later on.



And this too. When I drove and fooled with cars with carbs I had a choke setting for late spring, summer, and early fall & a setting for all other times. On the electric choke housing was a pointer and on the plastic housing you could turn to change the setting it had a bunch of tick marks. I got it adjusted how I wanted it and painted RED on a tick mark for the first setting and Blue on a tick mark for the second setting.

 

I saw the tick marks on the electric choke and had no idea what that meant! I had not looked into in depth yet. I have already replaced the rubber fuel lines, fuel filter, fuel pump, added an insulator to the pump, and now the 1906 Edelbrock (650CFM and electric choke).
I will say the car starts easier and runs more smoothly, but still has the issue above 70mph or if I'm going too hard off the line. I can drive more like an adult (boo!) but can't get on the interstate due to not being able to stay at speed for more than a few minutes.

"I'd recommend checking the gas tank for crusties built up in the fuel pickup and lines," How do I do this?
Unfortunately I don't have anyone around here that will tune a carb, or at least an Edelbrock, that I am aware of. Everyone I've spoken to has said "first thing I'll do is put a Holley on" or "you know that is a boat anchor and you should just LS swap it." JUST LS swap it! Don't have the time or money for that right now!

 

Finding someone around you who is capable of properly tuning a carburetor is about as likely as finding an honest politician.
You probably should just take the time to learn. The standard Edelbrock tuning manual that comes with every new carb tells you how to do it.

Edit: and I agree with sofa, it's probably a fuel delivery issue and not so much a carb tuning issue (although a tune of new carb is a must).

 

Certainly true about an honest politician! I have the carb tuned to where it runs well the majority of the time, just under those special circumstances where it gives trouble.