'91 Laser idling problem

Help! My '91 Laser 2.0 RS Turbo has an idling problem. It hunts up and down between about 1100 and 1400 RPMs. Used to be rock solid at 750 for years. I've had it to 3 different mechanics. 2 of them were stumped. 1 of them (a Plymouth dealer) said it needed a new $1200 computer. Does this sound like a computer problem? I do not have a check engine or any other idiot lights. 2 of the mechanics said they hooked up to the computer and it reports that nothing's wrong.
One other problem I noticed: When I let up on the accelerator the RPMs go UP for a second or so before dropping. Makes for a real jerky ride at low gears. If I need a computer where could I get one. I can't put $1200 into a 13 year old car...

Andy

Check out www.dsmtuners.com/forums .

Check out www.dsmtrader.com for parts.

My bet is on a bad BISS screw/o-ring (2 dollar part), or the ISC motor (80ish rebuilt).

Most of the DSM guys hang out in the Mitsubishi Eclipse forum on here, so you would get even better help there or on Tuners.

I'm looking at a 91 laser rs turbo anyone help me with pros and cons, what to look out for? thanks

Do a diagnostic on it.....hook a ohm meter up to the diagnostic port on the driver side.

It could be one of 2 things or both, the TPS or the coil pack.

Check your BISS screw, idling is a big problem with these cars, as it is with mine, it doesnt bother me so much, and i have tried everything, how about 93 octane gas, this car is amazing 100mph in 3rd gear. Talk about bang for your buck i paid 1700 dollars and only have minor mods on it. Needs routine maitenence however.....