I have a 95 Cav that just had the engine replaced, it has 80,000 miles on it. It ran fine for about one week after engine change and then the battery light and Check engine light came on. Replaced the alternator after having it checked and hoped it would also fix the surging and high rev problem. It fixed the battery light, but thats it. The problem is that it when started it revs high about 5-6000 rpms. Then after it warms up good it drops to about 1-2000 rpms and surges between those. I have thought it may be the throttle position sensor, or maybe the idle air control valve, any ideas?

i would say either IAC or TPS like u think...

I replaced the iac and the map sensor because thats what the odb scanner said was giving me the check engine light. This caused the check engine light to go away but it still revs up to about 4500-5000 RPM on startup and stays there. Any help?

I finally figured out the problem it was actually the gasket on the throttle body to the intake manifold. It had a chunk missing. I sucks because this was the only gasket we changed when changing the engine and I had already spent all this other money on the different sensors. However, now it runs like a charm.