Hey guys.

So when my y-block is moving it does great, speeds up, runs at a constant speed nice and smoothly with no hiccups. You really get the feeling that engine wants to keep going and wants to go fast. Only problem is after I've been driving long enough to get the engine hot, the engine will want to sputter out and die when I come to a stop and slow down to idle speed unless I hold one foot on the break and keep light light pressure on the gas to keep her going.

I've noticed if I put the car in park and give it some pumps sometimes the idle will smooth back out and stay running again, so I don't know if it's a transmission thing or not.

Last time when I got her home hot and wanting to die, I managed to keep her running well enough to roughly idle while I got under the hood. I noticed if I started closing the choke-plates (richer) the engine would start running better and the problem would be fixed. But I know that's weird, the hot engine should be running with the choke all the way open shouldn't it? Anyway, I turned the knob on my auto-choke so that it'd keep the choke half-closed when the engine is hot. That's kinda fixed the problem, but still sometimes not..

I've also turned up the idle speed, and adjusted the clearance between the accelerator arm and the dashpot. All that seems to have helped. So maybe it's just a combination of little adjustments between those three things that I need to do?  But it still bothers me that the engine is needed the choke half-closed to run hot. I've heard maybe it's not getting enough fuel? I don't understand why not though, it's got a new gas-tank and new fuel pump installed and the lines are clean as far as I know.

Any advice?

You don’t mention what carburetor you’re running but at this point double check all tuneup specifications.  That means timing, point gap, ignition advance curve, idle fuel mixture, etc.  If having to run with the choke activated after the engine is hot, then look for a vacuum leak.  Beyond all this, the carburetor float level may be low which will require removing the top from the carburetor in which to check.  If the carburetor hasn’t been kitted lately, then it may simply be in need of a good cleaning.  Today’s ethanol laden fuels are extremely destructive to carb internals if not driven regularly.

Lorena, Texas (South of Waco)