If there is any way that you can get it checked for codes that would be VERY helpful. AutoZone, Advanced Auto Parts, Lee Myles trans... and others will pull codes for free.
For about $80- $100 you can buy your own code reader. You should have an OBD II system.
Look for vacuum leaks. If any of your vacuum hoses look cracked or brittle (dry rotted), replace them, if they are loose at the connector, they may be stretched, cut off the end and reconnect them.
Check for spark. Pull a plug, hold it against the block and have someone crank the engine.
Let us know your results, perhaps we can help more from there.
joe | 
