Keep in mind this idle/hesitation issue has been an issue since i bought the car before I did any of these repairs upgrades. the car was completely stock owned by an old lady.
here is what Ive done so far:
New Parts:
All intake sensors
All coolant sensors
Gt40 intake (explorer)
Gt40 fuel injectors (explorer)
Bbk H-pipe
Fuel pump
Fuel filter
Fuel pressure regulator
Coil (accel), cap&rotor, wires, plugs (accel)
Distributor (I did not buy this or install it. It was already on the car when I bought it, but it is brand new. not sure what brand and the car did sit for over 7 years)
3G Alt
All vacuum lines
O2 sensors
TPS
New to the list:
70mm MAF from 95 mustang
The vacuum line solenoid thingys mounted on the pass side shock tower
the vacuum valve thingys on the smog pump line.
Cleaned Parts:
EGR
ICV
TB
Checked for vacuum leaks via propane test = passed
no fault in computer cyl bal test pass
I have also changed out the IAC with another known working IAC and still not fixing the problem.
the only two things I haven't touched is the MAP/BAP sensor and the ignition control module. But I was told that the ICM doesn't go out slowly it's more of a just quits working type of thing so could it be the map/bap sensor would that cause idle and hessistation issues? Can I clean this sensor or is it a replace only type of thing? I'm also thinking maybe I have a vaccum leak in the havc system cuz that's the only place I can't test for a leak with the propane method so is there a way to bypass the entire havc vaccum system. To rule that at?