Pump is one I bought at O'Reiliy's when i was broke down on the road. It claims 3.5 psi and I can't remember how many GPH but it seems more than enough. It's replaced a pump with too high a pressure, 6 IIRC. that one had all the usual over-pressure symptoms. This situation is different in that is only does it in hot weather and high altitude after shutdown. No symptoms of leaking needle valve at idle.
