#1 is a bad ground.
#2 check for a vacuum leak at the manifold to. Spray carb cleaner around any vacuum ports, the intake and throttle body, if the idle drops you found your leak. Also may want to pull the IAC out and clean it and the passageways. A sticking IAC could be the culprit.
#3 doubt it's the pump, could be lifters or timing belt.
97 Sahara, 74 Renegade, 72 CJ5, 55 Willy's (the Beast) Boss 302, 6:34 gearing, Bose 901 speakers.
God I miss that Jeep. Forgot the kinda Jeep, 80 SX4.