87 r10 big cam, idles high

[tater502]

I traded my 93 for this 87, someone put a bigger cam(dont know the specs) and chip (motorvation 777) in it. When I first start it the idle is normal and I can really hear the cam, after a few seconds it idles higher and doesnt come down. Stock air filter and exhaust, no converter. No codes.

Ive replaced the fuel filter, pcv, plugs(old plugs were black), wires, cap and rotor, throttle body gasket, tps, iac, water temp sender, and looks like the O2 sensor was replaced too.

Before I go through all the trouble buying a stock cam cam and computer is there anything else I should check/replace? Timing or?