Need help with Holley 750
 

I have a 4779 Holley on my crate motor stocker.
It worked fine at Darlington and Piedmont. This weekend it developed a hesitation leaving the line. Does'nt hurt E.T. Just reaction time.

I would like to send it off or just buy another carb.
Any suggestions.
Thanks
Chip

Re: Need help with Holley 750
 

Call Billy Plage.He has mine working fine.1.32 60ft

Re: Need help with Holley 750
 

Put bigger squirter's in it.

Re: Need help with Holley 750
 

clean out the idle bleeds, they are probably dirty

Re: Need help with Holley 750
 

Before you do anything major check if both accl pumps are working. If one is dead pull the squirter and see if the check valve under the squirter is stuck. Take a small pick and move it around to get it unstuck. Be careful not to let it go in the intake it is not magnetic. If it is stuck the accl pump will be very hard to depress with your finger. If it was working/ running OK and now it is not this is most likley your problem. Is it running OK other than the stumble? Hope this helps, Mike

Re: Need help with Holley 750
 

Chip easy fix squiter...see what size it has& go up a couple sizes. One other thing..dose it have jet extensions in the secondary? oh almost forgot Cheap fix (or atleast try) rubber hose from the front bowel to the back....it may be dumping fuel from the front into it the carb on take off . make sure to cut a couple small holes in it for air. good luck;)

Re: Need help with Holley 750
 

Chip,
1. Check idle air bleeds for obstruction
2. Check accelerator pump adjustment and function
3. check pump discharge for obstruction
4. check timing, if timing is still same then go up 1 size on squirter and see if it clears up. If weather is close to prior runs and this did not happen then I suspect timing is off or trash in circuit somewhere. If DA is different then it could be a lean condition and squirter size change should help.

Re: Need help with Holley 750
 

All good advice. But I also believe the air was better this weekend, especially on Sunday.
If your squirters were borderline lean, the air could have leaned them out more. (footbraking)
If you're 2-stepping, it could be borderline lean jetting.

Re: Need help with Holley 750
 

The idle air bleeds won't cause it to hesitate, it would just sound like a V-6 at idle if they are dirty.
I'd say to go up on the squirters.

Is that the Texas two step you are talking about Myron? If Chip is a little lean doing that, maybe someone should have took him a couple beers! No wonder it took till 300 am to finish that race Saturday!

Re: Need help with Holley 750
 

I'm footbraking between 2000 & 2500 rpm's depending on track.
The air saturday was similar to the first 2 tracks.

It is a brand new carb.
Sunday Morning:
We went up on the squirter.
Went up on the timing.
Raised the floats
Adjusted the pump arms.

It did fine the first 3 passes. 3rd rd I dropped rpm to 2200 and it did it again.

HELP ME HELP ME HELP ME.
Chip

Re: Need help with Holley 750
 

Chip call me ..../I think i can help...

Re: Need help with Holley 750
 

>> It did fine the first 3 passes. 3rd rd I dropped rpm to 2200 and it did it again.

Oh, ok. I didn't get a chance to talk to you after the run. I figured you'd only give me an .022-.024 after being .000, so I was surprised at the .04. I figured maybe the polished rims blinded you. ;) I have no excuse for mine!

Re: Need help with Holley 750
 

First make sure all the passages are clean. If you still have the power valve, take it out and plug the hole. Go up 2 or 3 on the jet. That is what made it go away on my Top Stock. Holley 4779

Re: Need help with Holley 750
 

Jeff,
The carb originally had the PV blocked. I like leaving between 2000 and 2400, at those RPMs it had a horrible idle. We put a PV in and rejetted. Carb idles geat now.
Thanks
Chip

Re: Need help with Holley 750
 

Sounds like your idle passages might be blocked. I had one doing that. Didn't like to idle, but seemed ok @ wot. Quick fuel fixed it at the track. Idle passages were blocked amoung other things. Took a lot. After it was fixed, it made enough difference to bust 2 8/34 gears and 2 pro trans. I assume it is an out-the-box 4779?. Usually a stumble is lack of fuel. Just got to find it. On the T/STK 360 we ran 76 to 78 jets on all 4 corners and no pv. We left on a 2 step, but it would launch almost as well footbraking. No stumble and we ran 7 lbs pressure. Still run 7 lbs.

Re: Need help with Holley 750
 

Jeff after reading your last post. I'm going to check all the passages. It is an out of the box new 4779. We all know the quality of new parts these days.
Thanks
Chip