Car wont idle, what could be the problem?

[91turbodsm]

I was driving home on the freeway today doing about 70 at 3k rpm. When I got into the fast lane and passed somebody, I got up to about 85. Then I put the car into nuetral and just started coasting. As usual, my car dropped down to about 1100 RPM's, then out of no where, my car dies.

So then I start it back up and pull off of the freeway. From then on everytime I would put it in nuetral and let off of the gas, the car would die. It runs fine at all other ranges except idle. I checked the PCV valve and it was fine. I did manage to get it to idle by turning the idle control screw out about five times but I know this isn't the problem. Also, the check engine light never comes on so I'm thinking more in the way of fuel or vacume.

Just wanted a few opinions on what to look for before I start tearing into it.

Thanks in advance,
Andrew

 

[luv2rallye]

Check the vacuum lines for leak or no longer connected.

 

[RSTurboFWD90]

Check the ISC, TPS and idle switch.

 

[wcpierson]

I had a very similar problem one time and it was caused by bad gas. I made the mistake of filling up while the tanker was there refilling. Everytime I wasnt on the gas the car would die. I ended up having to get on the highway and drive around for a few hours to burn off the gas.

 

[95'clipseRS]

I have a similar problem, and I do have bad gas like wcpierson. However, I would definately consider checking you ISC, it's that or a vacuum leak.

 

[tqmx1]

When was the BISS Oring changed last? Mine did the same thing changed the ring and never agaim.