Help, car dying

[97MitsuEclipse]

I have a pretty modified GSX (see profile for parts list) and sometimes when i start it the rpms drop very low (like 200-400rpm) and sometimes bounces off of the 0 mark. Then i put the car in reverse and release the clutch, when i put the clutch back in to shift to first the rpms drop and the car dies. After driving for about a minute the rpms go back to normal and never drop below 800. This happened twice today. Any ideas of what is wrong? Should I be reving the engine or waiting for a while after i start it? Any help will be appreciated, Thanks

 

[Spln_Hrd]

as a mechanic I would get on it with a scan tool and look at the basics like fuel trim and stuff, but where you dont have access to fancy stuff like that. I would suggest looking for vacuum leaks, and see where that gets you. I like to use brake parts cleaner and spray it on all of the vacuum lines comming off the intake, the t.b. around the injectors, and where the intake manifold meets the cylinder head, if the idle goes way up when you spray a certain spot, that is where your leak is.

 

[Defiant]

Check to see if you've lost your idle adjustment screw.