Hi I own a 83 Chevy Scottsdale with the 305. Ever since I got it has been hesistant. I just rebuilt the third carb (Rochester Quadrajet) on it, and it runs worse, and now surges around 30 to 40. When I floor it it runs fine. Could this be a faulty accelerator pump or bad bushings? I also just replaced the distributor. Would it be better to replace the carb with a 650 cfm Edelbrock or replace the accelerator pump, or is not a fuel problem?
Thanks

 

Im leaning towards vacum leak. Use some starter fluid to spray around the base of the carb to see of the idle goes up while doing this.

 

Thanks, I'll try that.

 

It seemed to go up in rpm when I did that. What should I do from here?

 

Ok that means there is a vacum leak which means its pulling air from where it shouldn't be. Try and pinpoint with that spray by throwing short bursts.

 

I got it fixed. It ended up being the combination of the Distributor and Carb. I love the way it runs, but is there any way I could get the gas mileage back to the 13 to 15 mpg I used to be getting? Thanks

 

Well its hard to fine tune the mixture on carbs but it can be done. Use a wideband O2 sensor and air fuel ratio guage.

 

Ok, thank you... I have Dyno close to me, would it be good to take it up there and tune it? Thanks

 

Im sure they have that equipment to do that.