Mitsubishi Repair: IAC, Mitsubishi Eclips 91, mitsubishi eclips, leaky capacitors

Question
My son is working on an eclips and would like to know what an IAC motor is and posibly how to check if its bad and how to replace it.  The starter works and engine turns but does not start.  Fuel is getting to the fuel injecter but is not going through.  He said the IAC is making a growling noise.  Thank you,

Answer
Daniel,
The Idle Air Controller (IAC) is a motor or valve that bypasses air past the throttle plate when the car is at idle (i.e. while you're not stepping on the gas pedal). It regulates the amount of air entering the engine and is responsible for maintaining a constant RPM speed at idle.  It is located under the throttle body, and any service manual will instruct you how to test to see if it's functioning properly.  

If the car is not starting, I doubt it's an IAC problem.  The IAC does not even function when the engine is cold.  That's why you're idle is always higher on cold starts and in the morning.  I've never heard of any reports of people indicating that a malfunctioing IAC was making any noise, but I guess it's possible.

The problem is most likely an ignition system problem.  Check the spark plugs, spark plug wires, distributor (if it's a 1.8L engine) or the ignition coil (if you have a 2.0L engine).  Any service manual will instruct you how to check all those items.

The last thing I can think of for you to check is the car's computer.  Read this article for further information:
http://90gsx.com/eclipse/cap/caps.htm

If the ECU is malfucntioning due to corrosion caused by leaky capacitors, it'll definitely cause starting problems.  Have your ECU inspected.
Good luck!