Holley sixpack issue

[ladd69]

I have rebuilt my sixpack on the 440 and iam Having some issues,
engine starts fine with a little gas.
idle is worried and dies when cold. I can get it steady by putting my hand on the tower.
the center Carb is hushing very loud.
my thought is a massive vacuum leak , but cant find any ??
the trottle response is fast but when i release the trottle it takes about 2 sec for the rpm to drop.

I changed nothing when rebuilding
feels like i am Having Way to much airflow, any ideas ?

thanks/ John

 

[6PKRTSE]

Try loosening all of the base plate bolts and snug them up evenly. If one is tightened more than the rest it could cause the base plate to flex enough that the butterflies could be hanging open slightly.

 

[PurpleBeeper]

Yes, make SURE your secondaries are closing quicly. You might double check to see if your carb linkage is TOTALLY clear of the side of the intake manifold. It will install backwards, then hold you at wide open throttle by dragging on the intake... I lost an engine that way.

IF your carbs are not hanging up in any way & closing on their own without the throttle cable connected....then either your throttle cable is worn, your carpet is making the gas pedal hang up, or your carb return spring(s) are weak.

As far as running....yes, it sounds like a vacuum leak OR a choke that isn't working properly

 

[WileE]

What is your vacuum gauge readings ?

 

[ladd69]

What is your vacuum gauge readings ?

Got no vacuum gauge available right now

 

[ladd69]

Thanks for answers, I really appreciate it! Pulled center carb and found this,
Is that my vaccum leak makeing airflow to high?
How does this happen to a new gasket?

 

[Orig69]

It looks like some of the carb studs are not screwed in all the way into the intake manifold.

 

[1968rt]

Had a very similar problem. I checked everywhere for a vacuum leak. Someone suggested warped base plates. Finally I decided to use two thick gaskets on each carb. Problem solved!

 

[ladd69]

It looks like some of the carb studs are not screwed in all the way into the intake manifold.

Oh yeah, maybe ran out of threads before geting enough pressure on gasket

 

[Mopar Miki]

I have rebuilt my sixpack on the 440 and iam Having some issues,
engine starts fine with a little gas.
idle is worried and dies when cold. I can get it steady by putting my hand on the tower.
the center Carb is hushing very loud.
my thought is a massive vacuum leak , but cant find any ??
the trottle response is fast but when i release the trottle it takes about 2 sec for the rpm to drop.

I changed nothing when rebuilding
feels like i am Having Way to much airflow, any ideas ?

thanks/ John

Lots of mistakes starting with use bolts not studs to mount carbs.
Carbs require a specific baseline set up - if this is not followed you are wasting your efforts. Do not listen to the idiots about cooling - the engine requires a 195 degree thermostat for the fuel to atomize efficiently. There is a guide on the lift off hood forum that should help you set up the six pak. Good luck

 

[ladd69]

Problem solved!

The center carb was pulling air trough the Hot idle compensator valve,
When i pulled the Carb apart there was a blown cork gasket, I replaced it with an O-ring (rubber gasket) and it felt nice and tight but wasnt.

I tried and plugget the valve totally and now it runs really good.

So all good besides The valve wont work since i plugged it

Thanks for answers and input