I have recently been working on a problem with a 350 boost referenced holley carb on my supercharged omni. While holding the throttle open, the accelerator squirters would start pushing fuel like they were injectors. I was told this was called pull over and was common on 4 cylinders from intake pulses. I called holley tech line and was told by them they make parts to eliminate this issue.. I bought they're anti pull over squirters which come on all spread bores (no help). Then they sold me a Mallory metal needle, heavier and they are sold and made to prevent pull over.(no help). Then They sold me a spring loaded needle. (no help). I was working on this for a long time. I made an adapter plate for the blower for a carter 625 comp. series carb. and the problem was gone. Because of the width of the carb it was hitting the firewall lip I couldn't leave it on. I called holley and they told me the problem was I needed more CFM with the Blower. So I bought a 500 Holley and boost referenced it and put it on. Right back to square one. I installed all parts the required listed above. (no help). They then had me drill a .020 hole in the pump passage on the back side of the metering block. They said this would let it suck air out of the top of the bowl and not fuel. That seamed to slow it up but I lost some squirt a the pump when needed. so (no help) I gave up. Then one day I was working on the duster it was running rich in the middle while cruising. It has a BLP 1000 CFM. I called them and they told me The emulsion jets in the metering blocks were not meant for mid range cruising. I put 850 holley blocks in and jetted it for the top. While I was holding the throttle open at 4000 I noticed the accelerator squirters doing the same as the omni. I thought to my self. What the F#@k. is going on here. I called up a Roundy round friend and told him what it was was doing. he asked if I had solid mounts. I said yeah I did. He said change the bowls. The new holleys from around 1990 on have a orange diaphragm check valve in the accelerator pump, this is a total seal and although better on a mild street car on rubber it won’t work on a steel mounted race motor on the street . while holding a steady throttle the pump diaphragm picks up a vibration with solid mounts and starts to pump fuel. through the squirters because the passage back to the bowl is sealed. He also told me this is why Quick-fuel still uses the check ball. I asked why it is never noticeable on race cars. He told me on circle track cars it is , under part throttle. But on drag cars your usually full throttle and jet accordingly. I put older holley bowls on the BLP and the problem was gone . I even put the billet blocks back on it that came with the carb. I then got the Omni back out and put a n older bowl on that 500. And low and behold it was fixed. I called holley and told them my findings. They told me yes they were aware of this but I told them I had pull over. This was not, it was pump vibration pressure. I got kind of mad and asked what are they going to do about the new bowls I would have to buy now . They told me this was my problem and suggested me to look at flea markets for old carbs because they don't make those bowls anymore, and I should have used their carb with rubber mounts as recommended. What a F#@kin joke. No wonder Every one stays away from holley. I am buying a new quick fuel as suggested. BLP bull shitted me to.
