I got a 88 cheif 4.0 manual 4x4. Has a bit of a high idle(anywere betweer 1000 and 1250) and ita random, hot or cold but mostly hot. Iv replaced the vaccum harness, replaced IAC, cleaned throttle body, set the tps cleaned the c101, cleaned the ground on the dip stick and on the firewall, replaced 1 factory crimp going to the c101. Maybe a few things i forgot The battery ground is on the dip stick stud but I'm wouldnt think that would make a diffrence. I'm thinking its t maybe a bad intake gasket.
Is there a way to test that without spraying carb cleaner or anything everywere? Or any other ideas on what to check?