1993 olds cutlass supreme idles between 3500 and 400rpms

A flat spot on acceleration could be low fuel pressure or a faulty throttle position sensor. Could also be a vac leak such as a faulty EGR valve.
Is the check engine light on ?

YOU SHOULD HAVE VACUUM AT IDLE TO MAP SENSOR.WIDE OPEN THROTTLE VACUUM WILL DROP. SO YOU NEED CHECK AND REPLACE ALL VACUUM LINES ON INTAKE MANIFOLD.THATS WHERE YOUR MAP SENSOR GETS IT VACUUM FROM.

replace throttle position sensor right underneath idle air control valve

You will need to change the crank position sensor first and see if it corrects the problem. It is located behind the engine near the firewall. It's a bit tricky to get to it, you would need to rotate the engine forward then look under the exhaust manifold and under the cylinder closest to the drivers side. Use a 10 mm deep socket to loosen bolt. After replacement and it is still stalling then you will need to replace the ECM (vehicle computer). If it turns out to be the computer, go to your local junkyard to get an inexpensive replacement Click on the link below to view the CPS, it is around $22

http://www.partstrain.com/store/?N=0&Nr=AND(make:Oldsmobile,model:Cutlass+Supreme,year:1993,brand:Delphi,part:Crank+Position+Sensor)&ptc=S1171391678W45d204bec356b&ptid=ptc45891f6tnywz&id=Olqtv7cphi





Olds-Cutlass-Ciera.htm">http://en.allexperts.com/q/Oldsmobile-Buick-Repair-826/f/1992-Olds-Cutlass-Ciera.htm

replace tps throttle posision sensor

sound like could be a vacuum leak check all vacuum lines air filter housing make sure no leaks check throttle cable

Sticking throttle linkage, or faulty idle control system.

soundl like idle air control valve sensor
try a clean .............if no better replace

try the throttle position sensor

I have the same problem too. Local chevy dealer says it's the fuel regulator.