[jimclemjr]

First thing I would do is replace the plug and do so with an iridium for life. Understand this is not a real Fuel injection system. It is a throttle body injector similar to the original GM Rochester type things. It squirts and atomizes the gas in the throat of the throttle body depending on rpm and location of the crank by CPS. If the nozzle gets a ethanol fuel bogger or piece of trash in it it will do what you describe. Static fuel pressure will build and give it a squirt but residual pressure while running is not enough.

 

[jimclemjr]

If you still have problem, look for a Youtube on cleaning an injector with a flashlight battery and a can of carb cleaner by spraying the cleaner thru injector. You do have a throttle position sensor and an idle motor also if memory serves and you need to make sure the throttle plate has proper clearance. Get a service manual, it is very helpful, well written.