Low idle and going dead

I have noticed in the last few weeks that when I come to a traffic light or stop sign, that my idle is really low. Also,when I take off, the engine wants to hesitate. Anybody have this trouble before? I put a new Jasper engine in it 3 years ago ( thanks to the gasket leak that GM will say that it is not their fault they put a weak gasket in these vans).

There is another thread where the guy has a similar issue. He didn't post back yet as to what solved his problem though. Its at http://www.automotiveforums.com/vbulletin/showthread.php?t=925732
I would suspect the manifold air pressure (MAP) sensor and the IAC valve. These two parts work together to set low idle conditions and engine pickup from low idle.
The IAC is located right at the throttle butterfly and allows air to get past the throttle plate when its closed. The MAP sensor is located right in front of the coil pack and measures the vacuum in the manifold.
Not much you can do the test the MAP sensor other than swap it out with one from almost any other GM car. These cost about $50 so its nice to be sure you need one first.
The IAC you can remove and inspect and clean. It is a solonoid type plunger that moves back and forth to open/close the air stream.

if anyone has been working on the engine just before it started to act up they could have knocked the map sensor line loose.or it could be cracked . the iac can be cleaned with a can of carb cleaner .