[rogerw11]

There are several things that can cause such a situation. I would first start with the easy stuff then be prepared to dole out the big bucks.

1. Check all vacume lines for break or deteriation.
2. Examine Spark Plugs for proper detonation (wet or dry)
3. Ensure Fuel Pump is operating properly.
4. Verify Idle Control Valve is not clogged
5. Ensure you do not have a clogged Fuel Distributor (internal Filters causes low fuel delivery).
6. Ensure you do not have a head gasket leaking (Oil on Spark Plugs - Oil in Coolant)
7. Try 2 bottles of Techron Fuel Injector Cleaner in less than a full tank of fuel for cleaning to see if that clears the problem.

I hope this helps.