carb help, hei, vacuum advance

[ebagsayz]

RE: Ok i have finally picked which lift

alright heres how it goes....258..bout 75 or 100k thous miles not sure, new k551 carb, new plugs, new wires, backfiring through carb like hell as rpms become higher...fine at idle...this backfiring is in CARB not exhaust..i figured maybe its running rich and perhaps not burning all fuel as i've heard in the past...installed MSD...bumped timing up, adjusted fuel air mixture, nothing still same...i cannot figure out how to take the idle jets out from the carb but i dont think thats the problem (about the jets i know they screw out from top..but they just wont fit through that opening i'm sure i can get it if i work at it..)...guy is telling me could be the vaccum advance perhaps, if so someone know exactly how/where to hook up any vacuum hoses to be on safe side...only need one to distributor i suppose..i also have a ticking valve it sounds like and someone else is saying it could be my camshaft is worn out or rod is wornand thats what is leaving me with the excessive backfiring, its hard for me to go above 35 mph..this sucks... any advice/questions welcome...thanks

 

[ebagsayz]

btw im also looking into getting a GM HEI distributor...DUI i guess, for this particular engine do you actually have to have a vaccuum advance, is there not any way to by pass this? anwyas lemme know

 

[lah2420]

RE: Ok i have finally picked which lift

I wouldn't expect the vacuum advance to cause this. Is your intake or exhaust manifold loose? That may cause the ticking noise. Also, if an intake valve doesn't close off you could get backfires through the carb.

 

[odjeep]

RE: Off topic: Know any soldiers or anyone overseas?

whats ur timing set at at idle with the vac advance hose removed and pluged? if its set too far before tdc it would cause a backfire through the carb when the advance kicks in. should be about 9-11 degrees btdc.
the ticking could be a loose manifold like lah2420 said or it could just be the rockers chattering away. its not the pcv valve rattling that u hear is it? theyre at the ends of the hoses that go into the top of the valve cover. hope u get it figured out.
od