I have a 69 Ford Torino with a 302 engine and a holley 650 carb that was rebuilt about 6 months ago.

My car just recently has developed a bad idle surge problem.

I have checked all vacuum lines and carb mounting.

The problem seems to be temp sensitive, runs good when cold but gets worse as it warms up.

The choke is not hooked up and not used because I live in SW Florida.

I have manual brake with no booster.

Car does not run rich.

Any help or ideas please?

Thanks
Rod and Alicia

If you have read the forum, You know I am going to disagree that your 302 is running rich with the 650.
But that is probably not your problem......... totally.

Yea 650 is a lot of CFM for that 302, which makes the air fuel mixture on the rich side, you probably got it running OK and maybe even good depending upon your engine and how you drive and what you did to the carb to get it tuned. But that was 6 months ago, 6 months on todays gas has probably got something fouling out in one of the (many) holley passages.

What is in all likely happening is when you are going from the idle system through the accelerator system and then onto the cruise system, because your carb/intake really has more fuel than can be used by the 302 cubic inches, you are getting a momentary (time being relative) overrich air/fuel ratio and its causing your stumble/hesitation.

Its a classic symptom, and is problematic with just what you described.

So how do you fix it.....

Wel you first need to see if its perhaps in the ignition system..... (WHAT) yep, that overrich often causes fouled spark plugs which amplify that hesitation. These would have to be fixed first and foremost our your whizzing in the wind.

Next you can see if you can either turn down the idles just a tad to take car of the hesitation or bump the timing to get things flowing a bit, moderation is the key, we are only talking about 25--no more than 50 rpm. This is a temp fix (at best) but can often solve small hesitations.

Real solution is to kit it, I know Holley kits are 25-75 bucks and with down time a pain but that is the solution. Holleys are tempermental this way and with todays fuel especially in your hot humid climate, you can expect this when running this combination.

Of course the REAL solution is to is to look closer at your engines needs and place a proper CFM carb more in tune with your engine. I know lots (I hesitate to say millions) of people use 600 to 650 on 302 type motors, but if you really amplify any problems when your carb/engine starts to foul up IF YOU GET IT RIGHT IN THE FIRST PLACE.
I have seen enough dyno time to realize even when people think they have a combo like this running right, IT ISN'T. You can see it in the temps, the horsepower and torque, and the exhaust analysis.

Hope that helps,

Bill White
White Automotive