Ford Repair: 1988 Ford 2.3 FI idle problem., vacuum leaks, air plenum

Question
Hello as above in a ford ranger. 300,000 kms. On start idle is high (old school FI i suspect) but after warm up it either shoots up to 1500 - 2000 rpm or it will idle properly and at other times it will surge up and down. I have 20 yrs as a brake and front end tech and a bit of diagnosing. My main question is where would the diagnostic link be on this vehicle. Can't find it under the hood. Hoping it's the same diagnostic tool as for the 2.3 tempos as that's what I have. No check engine light that I know of, or possibly inoperative. Also is there an idle speed motor or is this possibly an emission problem, egr etc.
                      Thanks : Daniel

Answer
dlc should be under hood on left or right fender-probably on right side under a plastic cover-be sure and check for vacuum leaks-dirty throttle bore and or iac motor-the iac motor if it is electric with 4-6 wires leave it alone and under no circumstances do you unplug it with motor running or within 10 seconds of shutting it off because that can blow the driver in the ecm on that model-if it is a electric motor in the air plenum with two wires take it off and clean it-