Vman73 said: Bill, no Holley expert here but hesitation is usually the accelerator pump or the secondaries opening too soon. Since you mention the acc pump seems to be working, I would suggest the secondaries. Does your Holley have vacuum or mechanical secondaries ?? If vacuum, it can be adjusted by changing the internal spring in the diaphragm. not sure about mechanical secondary adjustment, check out the Holley website, they've got some good technical resources there. There are also a coupe adjustments for the accelerator pump to consider, the pumps should have adjustment screws plus the nozzles can be changed to larger dia. holes to deliver more fuel, again check out the Holey website for more info. Hope this helps, let us know what you find.
I thought we were on to something with the secondaries opening too soon. Looking at them there was a bit of play where they could open with little resistance, so I put a light spring on them to hold them shut tighter. Problem solved, I thought... but when I took it out again -- same issue.
The engine has good steady vacuum (27 inches) so it looks like the intake valves and idle adjustments are okay.
I looked at a Holley forum and got some good pointers there, but nothing seems to point to a resolution.
Thanks again!
______________