Tuning

[carhead22000]

what temp is the car at when idle starts messing up?i,d get it running good then address the stumble at start by playing with the pump shot.give it some more fuel at launch. Unless its running hot. Then your fuel might be vaporizing in carb.that wold cause idle to be jumpy.

 

[Rustbucket350]

If your friend thinks the timing is set properly then it's time to buy your own timing light. I hear a lot of people say whatever they want about timing. Nothing is better than checking it for real with a timing light.

 

[1320feet]

I have it tuned so there is no hesitation or stumble when you hit the gas. If I tune it so it idles good I get a stumble when I hammer the gas from a stop.

What are you changing between these 2 scenarios?

 

[G72Zed]

Friend thinks the timing is around 36-40°

As the old saying goes, "If you think you know, you don't know" Hence my question in post #10.

Before carb changes can be done and evaluated, the timing has to be on par as with the ignition system.

 

[serpent710]

What are you changing between these 2 scenarios?

Idle mixture screws on the side. All 4 corners, go out 1/2 turn and stumble is gone.

 

[1320feet]

Sound like you need to leave the idle screws in where it idles nice and increase your pump nozzle area, try 2 sizes up.

 

[COPO]

Timing between 36-40. That’s a big diff. Get a timing light as suggested and set it to 36* all in at 3,000 rpm.
I like old school, my non digital.

 

[cnlmustard]

If the carbie started the engine to have difficulty when installed, what was there before? (if it aint broke dont fix it).
Put the original back on, and you might be surprised how good it used to run.
Is the intake manifold stock? Because the two have to compatible big time.
Call Holley, they will tell you. They actually swapped mine with the one they felt could deal with my new manifold.

 

[serpent710]

Newest update: Changed nozzles. Went up and down,28-37.It has 35 in it. Changed cam from green to orange, Changed screw on cam from spot 1 to spot 2. Adjusted the accelerator pump, main and secondary so there in no play. Next I guess I have to check the main jets and the timing.

 

[serpent710]

If the carbie started the engine to have difficulty when installed, what was there before? (if it aint broke dont fix it).
Put the original back on, and you might be surprised how good it used to run.
Is the intake manifold stock? Because the two have to compatible big time.
Call Holley, they will tell you. They actually swapped mine with the one they felt could deal with my new manifold.

Had an Edelbrock 750 in it and went to a holley 650. Intake is a RPM air Gap. I might be giving Holley a call lol