Mitsubishi Repair: Engine surge..., body assembly, idle air controller

Question
My 4g64 engine in my Spyder has been-on occasion, surging at low RPM.  Sometimes it will even die.  Has new Timing belt.  Has been well maintained-always.  No doubt a sensor of some sort.  Any idea's?

Answer
Jack,
This can be caused by a failing alternator.  With the car running and at normal operating temperature, the easiest way to get the alternator is to find the voltage across the battery terminals.  If you have a voltmeter, the voltage should be around 14.5 volts.

You should also have your throttle body assembly inspected.  There is a component attached to the throttle body called the idle air controller (IAC.  This component's job is to regulate the idle speed once the engine has warmed up.  If this component is malfunctioning, you will get idle surges and even stalling.
Good luck!