Anybody got the end all cure for vapor locking?

Posted by 1929PackardGuy On 2021/12/30 17:41:17

My '29 has been giving me fits the last couple of weeks. All of a sudden started running rough and stalling at idle, but only after the engine was hot -180 degrees or so.

So, changed condensor, almost killed myself changing the coil under the dash, changed the plugs, filed and gapped the points, car runs fantastic now, better than ever, until it gets warm - about 180. Not spitting and running rough like it was, seems to be just plain old vapor locking. I got the car last August, drove it a fair amount then when it was quite hot down here and never had an issue with this. Now it wants to stall once she's good and warmed up. Experimented, leaving the hood open on carb side, she runs fine, doesn't try to stall.

It's running an electric fuel pump, gravity pump is dead and gutted, but again, it ran fine until the 22nd with this exact same setup. Also changed the fuel filter. Have read the winter blend gas may be part of this issue, running non-ethanol 87 octane fuel. 1-1/2 psi at the regulator, tried upping it all the way to 3, made no difference.

So, anybody got ideas? I've read about people adding all sorts of things to their gas. Finally, this is Louisiana, it was 88 degrees here today with 65% humidity when she started having problems after about fifteen minutes of driving. Thanks!!