You could go to a local auto parts store and buy a SPARK TESTER. With this you can test each wire with engine running to see if there's good spark on all cylinders. The best way is to use a good scanner to see which cylinders are NOT firing. Could be plugs....wires..... bad/weak ignition coil..... etc.
Another thing that might be in the mix of that poor operation could be a bad coil or a bad ignition control module. And check for any possible vacuum leaks. Pull the cover plate where the PCV valve is to be sure the O RING is still good also. Mr goodwrench
A forum community dedicated to all General Motors makes and models owners and enthusiasts running the 3800 series engine. Come join the discussion about performance, modifications, classifieds, troubleshooting, builds, tunes, superchargers, maintenance, and more!