moose4130

I recently purchased an s14 with an sr20det swap already done. It was done with an s13 ecu with nistune and wiring spectialties harness. But, I've discovered it gets very hot after driving normally for 10 minutes or so. But, if accelerated hard, the gauge drops to normal temps. It doesn't seem to get overly hot if just idling. After shutting down, it seems to cool off kind quickly, and just after shut down, the engine, upper hose, and top of radiator are very hot, but lower hose is cold/ambient temp.
The car has an aluminum aftermarket radiator, dual electric fan with shroud, and a new thermostat. I tried to bleed the system with the bleeder screw, but it was seized in the outlet and broke off. So I filled the system with a spill free funnel while squeezing and massaging the upper hose until I couldn't get it any better.
Any ideas? I am thinking possibly air in system or bad impeller, but the water pump looks newish, though I know that means nothing.