When the car idels the rpms will go up and down and the engine almost stalls

Depends on your cars set up but on some engines there is a device either electronic or mechanical that keeps the throttle from decreasing too quickly(inhibits rpms from rapid deceleration) so you don't feel like your car is down shifting while coming to a stop. If it becomes gummed up it will stick causing the problem you are describing. You can usually clean it up with a little dis-assembly and a can of carb cleaner.

Check your EGR valve, see if it's stuck open. Next look for vacuum leaks, then check cam timing. Check engine light on? If so, get the codes.

What you may need is a 2000rpm stall converter. It is a converter that has fewer plates inside it and so is less efficient at low rpm's . IT works at around 1500 - 2000 rpms when the engine is approaching the torque performance curve.. BY suit up engine I take it that you have had extensive engine rework to make it really go, in which case a standard converter loads up the engine and stops the cam shaft and air flow from operating correctly hence the stall situation.. They cab be bought from speed shops that specialise in reworked transmissions

You'll have to figure out if it is a fuel or ignition problem.
Is the check engine light on ?

If you don't have a check engine light, Start with the air and fuel filter, work your way up to a tune up. Clean the throttle body as best you can on the inside, behind the throttle plate/s

Plugged air filter - replace.

Dirty throttle body and idle/air control motor - Can of Carb. cleaner sprayed into throttle body and idle/air hole while engine is running.

If engine is also running rough check:
-Spark Plugs.
-Compression for bad valve.

sounds like the throttle position sensor, I think that is the one that makes it idel rough

if this is a 97 you have just one belt ,this is kept tight by a tention pully ,as far as the ideling it sounds like the throttel cabel has come loose this is just a guess but this can bee check fairly simply .i would suggest geting a manuel from a local part store about $15.00 hope this helps

its vapor locking try leaving the fuel cap a little lose!!!!

Almost always a vacuum leak. Especially suspect is the vacuum "boss" located near the back of the engine. Make sure all those little hoses are on their nipples, and that the hoses themselves are not cracked, etc.