I was driving down the interstate yesterday in my 65 289. Humming along at 70mph I needed to speed up to avoid a merging lane of cars. When I got on the gas at 70, the car accelerated great for a few seconds then starts to hesitate and stutter. Only happens during this scenario. This has been something since last fall that I have not been able to cure.

The lower end of the engine was ok when checked last year.

The original heads were completely rebuilt last year.

Using an Edelbrock Performer cam/Intake/600cfm carb.

Electronic Ignition

New Coil and Fuel Filter


My guess is that it is either electrical or fuel problem. Since I am using a more aggressive setup (Edelbrock Performer cam/Intake/600cfm carb), my gut tells me that the original fuel pump can't keep up at that speed/rpm???

Any advice or help would be greatly appreciated.

 

My guess is you are right and it is a fuel issue. Does it only happen at highway speed or is it every time you get on it?

 

only on highway, not when i get on it at a complete stop.

 

Could it be your plugs, Wires, Rotorcap or rotor?

I don't think it is you fuel pump if it is working right. Could be wrong. Maybe fuel filter or something like that. How about your floats. Are they set right?

 

Don't forget the basics like cap, rotor, wires and plugs....

 

By your description, it sounds like a fuel issue. That happened to mine a few summers ago, and after checking out eveything electrical, I started with the carb and worked my way back. Well, I wound up taking the sending unit out of the tank, and lo and behold, the "sock" filter attached to the float was mostly clogged with that brownish stuff called rust. So, a clean sock, and all was well. Which reminds me. I need to change out the tank this summer.

 

plugs and wires are new, although i need to check the gap.

don't know what floats are and how they are set? Something relating to the distributor?

 

appreciate all the input. need to check rotor/cap/dist./plug gaps/tank components, and probably replace the fuel pump.

 

your float levels have to deal with your carburetor. if you have a four barrel you have two float bowls with a hollow metal float in the past made of copper now made of some plastic. Float bowls are where your carburetor holds the fuel and the floatsm, float on the fuel. generally you have a flat head screw on the top of your carburetor with a nut to keep it tight. This adjusts your float level by moving your needle up and down on the float. the needle closes when the fuel level is high and the float is high and pushes the neddle closed, closing the fuel supply. you should have two little plugs on the sides of the float bowls. you adjust the needle and seat until the fuel level is right below the sight plug. clockwise lowers the fuel level. becareful i have never experienced it but heard many stories of liting a fire while trying to do this with the engine running. which you have to do. just keep the nut snug while you adjust. i would get a book and fully adjust your carburetor. sounds like a fuel problem.

 

it is deff a carburetor prolbem . it ant changing from the cruse to the accelerator circuit fast enouf .... thats whare the bog is comeing from what make is the carburetor. A stock fuel pump will have no prolbem keeping up with a Edelbrock Performer set up

It ant going to be just at 70 MPH . try this find a oppen strech of road olny do about 35, 40 MPH get the tack to settle in about 20 22 R's then snap the throttle oppen bet you it does it thare to