Starts easily when cold with a couple of pedal pump primes, and runs excellent.
However, after it has warmed up, if I turn it off, it is harder to start again. I find that I have to crank for longer with the gas pedal held about a quarter of the way down. Eventually it catches and, again, runs well.
Except... after it is fully warmed up, when I let off the gas (between shifts or to stop), it is often very slow to return to an idle. When it is cold or just warming up and I release the gas, the RPMs drop immediately. The hotter it gets, the more it starts to drop the RPMs very slowly when letting off the gas. Eventually it does get back to a proper idle, but can take 10-15 seconds (guessing, not actually timed). So, when I come to a light, push in the clutch, let off the gas and brake, it often races at starting around 2,000 RPM and gradually drops to normal.
Oddly, sometimes it just drops to an idle like it should (most of the time not).
Any ideas? Perhaps a bad choke? It is a Holley 4bbl that is only about 18 months old.
