I have a 1989 chevy blazer with a 5.7 liter. I have changed temp sensor and throttle position sensor, but still have high idle. Wondering what else to check to remedy problem?

. Clean/replace Idle Air Control Valve/hoses, throttle plate, throttle body, and ports. Here's what the IACV looks like:

http://shop.advanceautoparts.com/ProductDetail.aspx?MfrCode=BOR&MfrPartNumber=21738&PartType=506&PTSet=A

This link may provide some guidance:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-7.html#post1054149

. Adjust throttle cable--this may be the heart of the problem. Likely, back off one nut and tighten the other.