When the carb is on the bench it can actuate from closed throttle to WOT and then snap back to the idle screw.... when install on the motor ('69 430) it will stick open at like quarter or half throttle... you can push the throttle arm back towards the the idle screw but it feels like it is hanging up inside somehow.... do the Q-Jet just have one gasket under it between the the intake manifold? it feels like it isnt sitting high enough and the butterflies are hitting either the gasket or the manifold... This is very annoying and i do not know what elese to check... also i mausing the stock carb return spring. thanks
Could be a gasket getting you in trouble, also could be worn throttle shafts that are binding once the four corners are torqued. Devon
I'd set it on the intake with the bolts loose, and see how it works. Then finger-tighten the bolts and check, Then tighten the bolts and check. You should be able to feel when and hopefully where it's hanging this way.
it starts to happen right before the bolts are tighten more than just by hand.. i looked at the gasket and it doesn *appear* to hitting.. the throttle shaft is tight with very little wear.. this carb had low miles on hard parts. im stupmed.. it has to be the gasket somehow
As Jamyers said try finding your bind problem that way , but sounds like you may have a warped throttle plate . Double check for gasket causing problem , even triple check . Good Luck
I forgot to say PLEASE use two return springs , from someone that has had the experience of a broken return spring when onlu using one
I have had the gasket hang up the secondaries before but yours sounds like it could be a warped base or something. A hanging throttle is too dangerous to just guess with so if you can't find the problem send it out to a pro. I agree with the dual springs also, had a friend total his 442 because of a stuck throttle. Steve
Yes I am a mechanic of many trades for my living, including the automotive field..if I cannot figure it out ill try a different carb...i also thought about two springs just for safety sake...i am still leaning towards gaskets.. is there just the one gasket or is there a combination of gaskets??.. the carb and intake are from different units so there was no reference.. and it is not being driven till the throttle problem is rectified thanks for the ideas keep it coming
You could take the carb off and just bolt the gasket to the base to see if it hangs over enough to make contact with the throttle plates, other than that using a flashlight to look down the barrels while you open the throttle is the only other thing I can think of. The fact that it binds after you tighten it seems to point to a warped base. Good luck!! Steve
