secondaries arent opening

[Brightyellow69rtse]

this is on my 750 vac sec. holley with a proform main body. it has the lightest (white) spring in it.  i varified this by using the paperclip trick on the rod. the clip was right at the top of the rod where i put it.  i took the whole pod off and checked function with a low psi shot of compressed air. it was leaking so i took it apart and checked it out. i couldnt find any damage so i put it back together, the tried the air again. the rod moved easily this time even if i put some finger pressure on it.there was still a little air seeping out of the hole the rod exits from. the cork gaskit looks good that seals it to the carb.

after doing this i trieds the paperclip trick again and still nothing.   it started to rain like crazy so my session was cut short.

the engine produces 12" of vacuum at idle at 3 1/4 turns out. thats the highest i could get it and the a/f ratio is good aswell at this setting.

i hald the throttle wide open and opened the secondaries manually and they flopped right open with almost no effort. so their definatly not hitting anything.

should i just replace the diaphram? or is there something else going on?

im seriously contemplating a doublepumper just not sure how big to go as i have a few more mods planned for next year.

[c00nhunterjoe]

How much is "low psi"? If air was leaking you probably popped th diaphram. I was never a fan of vac secondaries.  My vote goes to the double pumper.

[Brightyellow69rtse]

pretty low im not sure but it wasnt much. it was under ten.  ill pull it apart again to check it out.

[firefighter3931]

Mike, if it's leaking either the diaphram or cork gasket is suspect. 


Ron

[Chryco Psycho]

the port feeding the vacuum from the venturi could be blocked , try some compressed air through there

[Brightyellow69rtse]

whats your guys thoughts on the steel ball? some people say remove it some say leave it in.  ill blow out the passages to make sure everythings clear.

[c00nhunterjoe]

Id getting working right before you modify it.  Still say if you had air coming out the diaphram or gasket is toast.