I have a slight issue that i could use some input on........My 1990 4.0 manual cherokee has an strange idle cond. .....I have searched and read many high idle threads....i have obtained a pdf copy of the test procedures for the renix system.....the 4.0 after initial warm -up will idle correctly......when fully warm it will idle correctly.... after giving a little gas in neutral lets say above 1500rpm the idle will not go below 1200rpm....if i then engage the clutch a little to bring the rpm's down below 1000 it will idle normal.....so i have checked and corrected vaacum leaks.....have also completly cleaned carbon from the tb and aic stepper motor......i have correct voltage input of 4.98V and output of .8v set on the tps...i also tested the output resistance range according to renix service manual on the tps all checked out ok....the ground also checks out...Here's the strange thing, being that when i unplug the tps during the slightly high idle cond. the engine rpm returns to normal....That makes me believe the sensor is bad ...but tests indicate that is good...if the tps is not bad....What would cause this???? and Why does the problem correct itself with the tps disconnected if the tps tests good??? .........I don't like wasting money on changing out good sensors......Can someone steer me in the right direction???
Thanks ..........................Matt
Thanks ..........................Matt