[1957willyman]

why is when i think i have everthing adjusted running good i shut motor down go back later engine will not idle you have to feather throttle sometimes it will idle sometimes not i have a msd distributor street fire what do ineed to do to this distributor does it sound like timing

[vinniekq2]

can you post a video?

[salvagesavage]

Originally Posted by 1957willyman

why is when i think i have everthing adjusted running good i shut motor down go back later engine will not idle you have to feather throttle sometimes it will idle sometimes not i have a msd distributor street fire what do ineed to do to this distributor does it sound like timing

check float level if its a holley !!

[salvagesavage]

Vacuum leakage ....... check everything....... retighten intake manifold bolts ect

[1957willyman]

this is a brand new crate motor from star performance products its done this ever since i bought it ive already had intake off resealed with new gaskets rtv brandnew 750 quickfuel carb got a very crappy motor not my choice of dealers if looking for crate motor

[salvagesavage]

Hmmmmm - ill bet the idle mix screws dont make much diff eh !! if so drill a eight inch hole in the front primary throttle plates ..... otherwise i have the thought you got more problems coming down the pipe .............
is it running hot ......... i doubt it is or you would have noted that...... anyway from my experience Holleys
the float level is too high ... so pull sight plugs and drop it a bit.... wont hurt a thing...... put vacumm gauge on and asertain you have proper vacuum ...... im sure you know how to set the ignition timing !! maybe pull valve covers and go over your valve adjustment procedure - zero lash add quarter turn..... otherwise maybe you got a camshaft going flat or other internal problems -it happens !!!!!!

[salvagesavage]

Hope this Helps yah a little bit ......... that engine should idle pretty good even if its not tuned that well really.......... i mean just pour the fuel in and the BBC is happy as all get out lol !!! years ago i built a mild 454 maybe 400hp deal....... and used to fire it up on two litre coffe can and idle....... 2 minutes of idling lol

[1957willyman]

yea not real experienced in this expensive hobby far as iknow got 22 degrees initial timing about 34 overall i do know if i pull the hose off the vachmn advance when it is idiling good it will die running about 210 with a 195 thermostat not able to drive thisthang yet so all iamdoing is idling it and reving up love to hear that sound lov it

[techinspector1]

Two things come to mind. Fuel pressure too high, overpowering the needle and seat and blowing raw fuel into the intake manifold.....and/or..... heat from the motor transferred to the carb bowls and boiling the fuel. Try a heat insulating gasket from Holley.....I'm not sure what body the QF carb uses, so choose the correct hole sizing and spacing. Be very careful when torquing down the carb studs to prevent warping the carburetor base plate.
Holley Performance Products Base Gasket*108-51

[1957willyman]

does timing sound right to you

[Greg T]

*************************

[salvagesavage]

timing is too far advanced - 22 dg initial omg
distributor probably has 20-24 degrees mechanical too
back the initial off too 15 degrees and plug in the vacuum can to full manifold vacuum