does it crank? CPS will keep it from starting not cranking. Battery disc. means nothing since you disc your battery. If the IAC goes bad your enigne will start but not idle, just replaced mine by the way. To check the CPS you can backprobe the elec connection by the intake manifold. The book says to discconct and ohm b & C and it should be open (overload). I don't like that way. If you have a anolog meter you can backprobe the connector one wire will have about 5volts (power from computer) one will be a ground, and other will be return power to computer. With the meter set up for voltage probe the ground and the return wires and crank the motor over you should see the meter jump from o volts to 5 volts when the engine spins (you do need an anolog meter not a digital it happens to fast for a digital to read). If you have any other ?'s let me know...
try and use an analog meter it will give you more of an acurate... often you will get E or OE when checking between b and c.... using the analog will give you a better direction for trouble shooting...
Before you go tossing a CPS at it, make sure your ASD Relay is good... Get a wiring diagram and just check that it's getting power ground and trigger, then make sure it is putting out.. These are known to fail and sometimes fail only to a point of passing reduced voltage. So just because it clicks dont mean nothing.. Been down this road and lost money (used to work flat rate) being fooled by a click..
I will try to remember how to make the tool, but I was shown a way of using a 9v battery and an LED to test the CPS... You disconnect the CPS from the harnass and feed 9v into one wire and then watch the LED flash as the motor turns (being cranked).. If I find the diagram I will post it here later today
99 XJ sport, Black, 4 door, 4 litre, 4wd
Black Jeep club member # 99
ASE Certified and professional Auto technician 12+ years
Every rose has it's Thorn, every XJ has it's leak, and every cowboy sings a sad sad song