Model A Downdraft Problem

Well, I am having a problem with my downdraft setup on my stock Model A.

Here is my dilemma- I got it to idle, and run great, but every time I go to brake, the engine dies on me... shoot! And it's only the motion of braking forward, I can idle to a stop, and brake in reverse...

Here are the specs: Ansen Intake, Reds Headers, Stromberg 97 with .45 jets and .65 PV.., 12v SW fuel pump, and my regulator is set at 3 psi.

I figured it was the float, but its not sticking and I set up the float so it is level when the inlet valve is closed... Did I do it wrong?

Can't quite figure it out.. What do you guys think? This week I am going to tear the carb down again, and check the float again.. thats my only guess as of right now.

Thanks~~

 

Well, let me (dis)qualify myself first by saying that I usually don't post over here on the HAMB, and I'm not real familiar with 97's. Regardless it sounds like a float level problem. I also would check your electrical sys. If it’s original, you have a positive ground so check your wiring polarity for the fuel pump. Also if you have the original style brake switch, they are notorious for shorts. I guess it is highly unlikely but possible to have the Fuel pump not work when you’re braking. And since there isn't much height difference with the tank in the stock location and an downdraft, then also have a problem with the braking G's or fuel slosh.......... just a thought.

 

I put on a modern fuel pump to see I it solved my problem.. But again it still dies on me when I go to brake.

I adjusted the float again and made sure it was perfect.. Still not working!

I can't figure this one out!

 

I know this doesn't help your issue but......
I had a similar issue on my stock Model A updraft carb.
I had to pull down my advance lever for a higher idle to keep it from stalling if I braked hard or on a downhill.
I no longer have the banger motor and just got used to applying the advance lever cause it worked.
I think mine was probably a float issue.

 

Yeah I have my advance down all the way. I can bring the idle up and it won't stall but it seems to be way to high of an idle. Maybe I haven't adjusted the air/fuel mixture correctly...

 

Ran into a similar problem on a downdraft conversion.I was running a brand new 97 and after reving the motor to a high idle and letting off the peddle,it would die.I thought for sure it was a float problem,but after asking around I learned these conversions work best with an elec. fuel pump.Instantly solved my problem.Good Luck!

 

yeah I got an electric fuel pump... but hasn't solved my problem yet.

 

Do you think it is dying from a rich or lean condition while braking? Does it "load up" and die?

Running my 94 with the float set low (to increase seat pressure) and only 1.5 PSI from the regulator.