It seems no matter what I do to my Holley 750DP it does not help. When I kick the secondary side in it has a flat spot. I want to be able to floor it from idle and the engine rev fast and smooth. I just cant get the flat spot out.
I bought a Holley tuneup kit with squirters, cams, and etc. I seem to have the front side working well. It has taken a lot of work to get it that way though. The engine is a 350 with sportsman II heads, 280 Hyd. Comp Cam, 10 to 1 comp., and an Edelbrock rpm intake.
To get the lean out of the primary took a blue cam in the 2nd hole a #37 squirter and drilling the primary throttle blades. The secondary is a pink cam 2nd hole and a #37 squirter. This helped some on the primary but the dead spot is still there. Could I need different jets?
I am about to go crazy trying to figure this out. I need help. Could some of you guys list exactly how you have your Holleys set up. Maybe your set up will work on mine.
I just want to stomp it and go smoothly is that to much to ask?

Welcome to the site, I think you have too much carb for your combo!! I have a 383 with 9.87:1 with SPII's, and a comp hyd roller 224@.050 and it would hardly open the vacuum sec's on a 780.

I downsized to a 670 and am much happier with it than the 780 performance wise.

I agre with Dennis, My suggestion in troubleshooting would be to remove the secondary pump lever and try it. It'll either improve or die. But then a smaller carb would cure alot.

What is the rest of the combo? How much gear? Convertor or std trans. A .037 squirter will usually require a Rio pump but you shouldn't need a .037 squirter. If the car doesn't have a loose convertor or an awfull lot of gear it will be faster if you only open half the carb from idle.

[ 09-08-2003, 01:25 PM: Message edited by: oger ]

I once ran almost the EXACT same combo in an 84 Camaro. I used a 700 DP and it was a little big for my combo, but I did get it to work pretty good in the end.

I went to smaller squirters on both the primary and secondary. I went 1 size smaller than stock - from .031 down to .028 if I recall. I stayed with the stock pump cams too. The big change that helped the most for me was jetting leaner --- like 4 sizes in front a 2 in back (going off memory here). Pump cams were Orange pos 1 in front and Brown in back . . . I think.

Sounds lke you are fairly close now, maybe the large primary squirter isn't letting the pump shot last long enough to cover the secondary opening.