93Rhinojeep

Question about my 93 xj 4.0l. I am trying to find out the source of my high idle. Just last year I changed the tps and the IAC on my Cherokee and now cold weather has came through and the idle is up and down up to a little over 1000rpm then gradually goes down to 500 rpm then almost shuts off and I'm sure there are a million reasons for this maybe o2 sensor, faulty tps, fuel pump,faulty IAC, fuel injectors, MAP sensor not sure any suggestions would help so I'm not throwing money at something that's not the problem. Also I took the throttle body off and the tps off separately and cleaned just the throttle body and also cleaned the iac still no resolution. So any suggestions would help for sure thanks.