I have a 92 SE. This problem just started. Vehicle will stall when drving down freeway, if I have the foot on the throttle it seems to be ok, but when I take it off the throttle and the idle comes down, it will stall (intermitent) however it has happened 6 times in the last 24 hours. It will not restart immediately. If I let it sit for about 10 to 15 min, it will then start up. I have changed the fuel pressure regulator, 02 sensor and plugs, wires last fall. Im thinking this is probably the fuel pump. The service engine light is not on. Any suggestions?

Just to add checked codes, I get 12, 17, 23, 58. I know 12 is just the diagnostic code, and the 23 I believe is low temp IAC sensor (I have it disconected from the air box), I did this after the problem started. 17 (spark reference circuit)??? and 58 not sure?? Does this info help????

http://www.bonnevilleclub.com/techinfo/?article=70

Check this out for code references.

You need to find out if it is fuel or spark. I think it is lack of spark. So when it won't start, you need to check for spark by taking off one spark plug wire, and using a small screwdriver to see if you get a spark to some grounded area of the engine, while someone cranks it over. Or use an old spark plug and hold the threaded portion against something grounded. Be careful, it might start. You should always provide a place for the spark to go, if you just leave a loose spark plug wire, then the spark may find another place to go, and burn a track in the coil.

My first suspect part would be the crank sensor, if it is spark.

A fuel pressure gauge is the best way to tell if the fuel system is working. There is a connector up at the fuel rail that enables you to monitor the pressure.

I had a similiar problem before, and threw a ton of codes. Eventually my tranny had to be replaced. The dealer told me something was wrong with the throttle, and gears were slipping on the tranny and thats why it was dying.....from what the GM dealer said.

Found it !! It was the crank sensor. When the car was operating at normal operating temperature, it was loosing it signal at a lower RPM which was causing it to stall. Thanks for the help!