Mystery Fuel/Carb Problem
 

'29 Tudor, '30 engine (stock), Zenith carb (new from Snyder's with 400+/- miles on it).
I needed a new muffler. Ordered one from Aries. Decided to also replace the manifold gasket.
Removed the carb, stored it upright. Removed the manifolds. Several days later assembled manifolds and mounted the carb.

Now I can't keep the engine running. If I pump the accelerator a couple times and pull out the choke with the GAV 3/4 turn open, it will run for 10 seconds, then stop. Like it's out of gas.

I don't understand what could have happened. I made no adjustments to the carb. It just sat on the shelf while waiting to be put back on.

Before, the car ran great and started within a couple revolutions of the engine.

I've taken the carb off and checked that the float is not stuck. Drained the bowl and see gas flowing through the sediment bowl to re-fill the carb.

Any suggestions are welcome.

Re: Mystery Fuel/Carb Problem
 

Since you had the manifolds off, I would look for an area around the intake manifold where air is being sucked in. Possibly a distorted gasket.

Tom Endy

Re: Mystery Fuel/Carb Problem
 

Did u turn the gas valve on? Just a thought! Goes up and down, not in line with valve!

Re: Mystery Fuel/Carb Problem
 

did you push the gas line too far into the carburetor?

Re: Mystery Fuel/Carb Problem
 

Manifold(s) leak?? Are you sure the muffler is (was) clear before installation??
Fuel flow?? Fuel bowl not filling?? Please keep us in the loop.

Paul in CT

Re: Mystery Fuel/Carb Problem
 

Yes, gas valve is on (up and down)

Fuel line was disconnected at the sediment bowl, only. Didn't remove fuel line from carb.

New muffler has not arrived. Starting w/o any muffler. Fuel bowl is filling.

Carefully checked gasket for alignment before installing manifolds. Trimmed excess gasket from valve cover gasket to make sure manifold gasket was flush with head. The manifold gasket is the two piece type that has holes that fit over the studs. Manifold nuts are not torqued - tight with 3/8 drive ratchet. Possibly not tight enough?

Re: Mystery Fuel/Carb Problem
 

Did you replace the carb gasket where it meets the intake manifold? Are those bolts snug?

Re: Mystery Fuel/Carb Problem
 

I'm with MOT, having done this very same thing with identical results.. Cheers

Re: Mystery Fuel/Carb Problem
 

Could be pushed to far in the sediment bowl... Same set up as carb side

Re: Mystery Fuel/Carb Problem
 

Did you use gland rings. Sounds like a vacuum leak to me.

Re: Mystery Fuel/Carb Problem
 

UPDATE: I decided to break out the torque wrench for the manifold nuts. Tightening to 25 ft/lb (about a half turn on the nut) there was improvement. The engine ran 30 sec or so before shutting down. I was using my normal starting procedure, not pumping the gas pedal.

Tightening further to 30 ft/lb got it running and starting normally.

Thank you all for your suggestions. It was very frustrating for me. Learned something from this. You guys are great!

Re: Mystery Fuel/Carb Problem
 

Don't pump the accelerator, you will flood it for sure!

Re: Mystery Fuel/Carb Problem
 

Don't worry about pumping the accelerator pedal. That won't flood the engine because there is no accelerator pump in the carburetor.

Re: Mystery Fuel/Carb Problem
 

We tole you, those are BIG bolts, tighten them accordingly! I do them 55FT LBS, in stages.
Bill W. & the Dog

Re: Mystery Fuel/Carb Problem
 

That's right! But the model A is VERY easy to flood by over choking.

Re: Mystery Fuel/Carb Problem
 

yup, just wondering if any one else saw that.

Re: Mystery Fuel/Carb Problem
 

My dad use to say; never put a new muffler on an old car, it will go bluuey for sure! :)

Re: Mystery Fuel/Carb Problem
 

pumping the gas pedal on an A with an updraft carb will have no effect whatever.
There is no accel pump and even if there were the excess gas would just drain out the carb throat onto the ground.
As stated flooding comes from over-choking