Rochester Carb issue 1966 Deville Question 429

[johwilli]

car ran great all summer. (over 800 miles) all conditions.  started it one day and it would stall when rev. Took to good GM tech as old as I am. He took it off I sent and had it sand blasted and re-built. He is at his wits end. Those two barrels continue to flow fuel and flood. Any ideas, thoughts, introductions to resources, etc are ALL WELCOME - Thank you in advance. Feel free to text or call 978 808 7313

[gkhashem]

Not a real genius on this but I think its's one of these.

1- Dirt not letting the valve seat because of dirt in the fuel. (I would guess not that since you have had it off and cleaned unless your fuel is bad)

2- Bad or incorrect floats, did he use a good float or the correct one when rebuilding.

3- Too much fuel pressure? Fuel pump worn or bad causing too much fuel pressure.

4- Dripping fuel due to expansion since the fuel line is getting hot and fuel is expanding past the needle and the seat. Did you move a fuel line closer to a heat source causing expansion of the gas?

Also if he is an older guy he should be able to rebuild a Rochester since many less experienced people do not know how to. I have 4 older cars, 3 with Rochesters one with a Carter. Many on here will trash the Rochester but mine all work fine. The Rochester was the GM in house brand so why would it be worse,if rebuilt properly?

[fishnjim]

I'd be having a little conversation with whomever "rebuilt" it.   They're problem, not yours.   a loud "FIX IT!" will suffice.

Typically, I'll say, do not sand blast a carb - of all things? 
Too many ways to get grit in the wrong places.   Sand is a little aggressive for cast aluminum anyway.   
You go down to the parts store and get a 5 gallon can or 2 gallons of carb cleaner, if you have a tank big enough, and soak it.   Takes all the gunk off.   Disassemble and soak everything.   Then wash and dry and clean all ports with a wire and air gun.  Looks like new.
Wish weather would get better today, so I can go outside and cease giving advice...

[Cadman-iac]

First off, is yours the old 4GC Rochester with dual floats,  or the Quadrajet carb?

["Cadillac Kid" Greg Surfas 15364]

66 would be a 4GC. QJ did not appear until 1967
Greg Surfas

[Cadman-iac]

Thanks,  I couldn't recall the first year for the Q-Jet.

Second question is, which 2 barrels are leaking,  the front  or rear?

The one nice thing about the 4GC is it's all based on the 2GC carb, which is about the simplest Rochester ever made.
The worst thing about the 4GC is that it holds 4 1/2 gallons of fuel. (Slight overstatement there)

[Jeff Rosansky CLC #28373]

I assume you just have the standard fuel pump?
Jeff