Holley DP Accelerator Pump

Yes, keep the bias of front to rear, relatively speaking. I would check the Holley specs and return it to what they had as a baseline, before starting to change things. As for the pink cam, I don't know what was original to it, but in a way it does not matter. I have a chart of the cam lifts and profiles. Let me see if I can post it here.

This burp or hesitation you mentioned, does it occur as soon as you hit the pedal, or does it launch ok and then fall flat?

Thanks!

Chris

PS: Here is some useful information, plus the chart of pump cams.

http://www.crankshaftcoalition.com/wiki/Holley_accelerator_pump



Edited by ccowx - Jul/31/2017 at 10:44am

You need to up the size of the squirters to maybe .031 and .035. I also suspect you will need to up the cam sizes, but do that AFTER you change the squirters, IF you need it. You can drill squirters out if you have a micro drill set.

Probably the reason you had improvement after going to hole #2 is that with your high idle you were already taking up some of the pump travel by adjusting the idle speed screw. You have in effect increased the pump stroke and therefore volume discharged by going to hole #2.

The stumble you get after you are already rolling will likely be curable with a different cam profile that is more aggressive at part throttle.

Don't get ahead of yourself with this. First, squirter size, next cam with higher lift and last, profile. You may find that issues clear up as you get the squirters and cam lift right for your combination.

Squirters are not sold in pairs and are interchangeable.

Chris

Well got some nozzles and the cam kit on order so maybe by weeks end I can try something. I'll post result when I do. Thanks for the help so far guys!

Bandana wrote: The stumble is immediate when I flip the throttle - although it did improve after I moved the cam to the #2 hole. I would also get some stumbling after getting rolling when I'd get into it and it would actually take a few seconds to recover once I let off. I think they sell the squirters in pairs? Can the front and rear be interchanged?

Increase the front nozzle size. You need more gas. Ccowx is correct on the reason why changing your cam to the number two hole helped as well.
spiritdude

So, latest update. Got my new parts and put a 31 squirter in front and a 35 in back. Throttle response improved noticeably. Still had a tendency to stumble off idle if I hit the throttle  fast. If I rolled into it slightly is was fine. Double /triple tapping the throttle after it got off idle was fine. I went ahead and took the medium blue spring out of the dizzy and now have both light silvers. I think this helped the throttle response some too. All of this is with the car sitting in the garage (monsoon day).

Thoughts on if I should try a 35/37 squirter combo - or go to cam profile changes??