Very small stumble at dead stop

[minifridge1138]

Hey everyone,

If I am at a dead stop and 'gun it' the car hesitates.
For less than a second, it starts to accelerate, then for less than a second the RPM's drop and it hesitates, then it accelerates as it should.

If I am gentler with the pedal, it doesn't happen.

Is this most likely an idle mix problem, an accelerator pump problem, or a timing problem?

Thanks everyone!

 

[JohnZ]

What carb and intake do you have on it?

 

[minifridge1138]

It is a holly 4160 750 cfm carb.
The intake is a Holley Street Dominator without EGR provisions (i don't know the exact model number).

 

[wishuwerehere82]

I would check everything you mentioned.
Do a tune on your idle mixture.
Check the vacuum advance and timing.
And verify that your accelerator pump is giving a strong shot on opening the throttle.

 

[rgtrough]

Hey Mini, This could be the classic Holley stumble. Do a search on this and you should find many troubleshooting ideas. Good luck.
peace Bud

 

[Hib Halverson]

Is the rest of the engine in the 82 stock or modified?
If modified, how so?

Looking at the bottom of the carb, where are the edges of the primary throttle plates in relation to the idle transfer ports?

 

[Copdogcorvettes]

Sounds like the accelerator pump to me; that's what happens when it's not working properly or at all. The only other thing is dist. timing.

Gary

 

[minifridge1138]

The rest of the engine is stock.