[SRSTANG]

When I accelerate from a stop the car has a hick-up as I drop the hammer; even when I accelerate slowly. I have a New Carb, plugs, wires, cap, rotor, fuel filer, etc. I checked firing order and I keep looking for vacuum leaks. Haven’t found one yet and I can confirm the gasket under the carb doesn’t leak. I have a fuel gauge (in-line) to confirm pressure. I suspect a vacuum leak, somewhere, or an adjustment is needed in the new carb. ANY suggestions from you would be great!! Thanks…rock on....

[My 5.0 91 LX]

try setting your tps yet, there are alot of post on how to set it ,I had the same problem and it cleared that up set it between .97-.99 use a mulitimeter to set the tps

[EagleAutosports]

He has a 1985 so he has no TPS to worry about.
What carb is it? Did it do this before the new carb and tune up parts?

[svnt442]

With it being a carb my initial thought is the accelerator pump. It it doesn't squirt then it will bog big time.

And it's a good question. What carb do you have? Stock or aftermarket Holley? Edelbrock? All needs to be known for a better diagnosis.

[SRSTANG]

Thanks for your support. Your advice/help is impressive. I wish I joined this site a while ago. It's a Rebuilt Holley 4BLL 100% tested at the Holley facility. This is a new problem when I upgraded everything including the carb., mechanical fuel pump, lines, and new fuel tank. They were all original with about 320Kmiles. Now with the new carb I can finally idle without giving it gas in 10 years. I will DEFINATELY look at the accelerator pump. (Not sure how yet) I checked the secondary chamber and the baffle plate opens fine. I was hoping the hood would be sucked down but all I get is this annoying hesitation. Thanks for ALL your advice....