Re: 1999 jeep grand Cherokee limited 4.7 V8 starting issue
I would start by taking the IAC stepper motor out (idle air control) and clean the plunjer and the whole air canal. Take care in not putting rotational force on the plunjer, or otherwise you will break the two internal plastic prones and you will have to replace the stepper motor.
The air canal begins at the front of the throttle body and should be cleaned from all dirt (so you will have to remove the resonator box as well). You will be surprised how much dirt can build up over time and jeopardises the idle control.
If this doesn´t help, it it most probably the TPS.