John Scott Posted December 17, 2003 Share Posted December 17, 2003 Been tuning in my new HP carb with one glaring fault. Every time I brake, it either stalls, or if really hard, dies. Eliminated booster leak. Tied bowl vents together with rubber line with hole on top, even routed lines outside the carb to eliminate fuel sloshing. Rear float level has something to do with it. I've set it so low its probably hanging in the oilpan, which helps, somewhat. I really have to rock the car to get any fuel out the site plugs. Fast braking in reverse shows no problems, only forward.I've never had this problem with any Holley or my recent Demon. On the good side, mid and top end are pulling so hard my eyeballs gagged me. Ideas, anyone? John Scott Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted December 30, 2003 Share Posted December 30, 2003 maybe try jet extension tubes on front jets.let me know-my bosses cobra kit car id doing this with a 850 4150hp carb. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 30, 2003 Share Posted December 30, 2003 Dang it, One other guy on this site and I had this same problem a while back, we discussed it, found a solution, and fixed both our cars, but I'll be damned if I can remember what it was. We thought at first it was loss of vacuum on an engine with already low vacuum at idle (due to my solid roller cam) anyway due to the momentary loss of vacuum when the booster calls upon it. But I think it was fuel pulling away from the jets in the front bowl under hard braking. Old age killing me here. I know you've heard this before, but try a search for this, in the text, because I can't remember the title of the string. It was last summer I believe. Good luck and complete this string so that it may help someone in a future search if you find the solution. This seems to be an ongoing problem. Quote Link to comment Share on other sites More sharing options...
John Scott Posted December 31, 2003 Author Share Posted December 31, 2003 Booster line is disconnected (testing only)so vacuum can't be an option. Primary jet extensions would surely starve the engine at launch, but may determine if it is primary side. I've tried w/wo on the secondary side. worth a try. Could g-forces of braking cause the fuel to stall in the jets at idle? Up the fuel pressure? Really like the HP carb otherwise, good cool air the other day the rear started to get away at the top of third, usually right on the ragged edge of traction :D Terry, if you remember, let me know. The only post I could find suggested checking the vent baffles. I know these carbs see plenty of track racing. Holley tech is of no help. John Scott Quote Link to comment Share on other sites More sharing options...
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