When ever my 90 is idleing or crusing I can feel the engine stumble, I put new ACdelco plugs in like last week, and it helped a tiny bit, But it'* still there. I also ran a bottle of fuel system cleaner and it remains there. Any Idea'*?

Test the coils. How old are the plug wires?

Im not sure, they were on the car when I bought it.
They may be new because the person who had the car before did good up keep,
but that'* also a hit and miss.
How would I go about testing the coils? haha

There'* a testing write up in tech info. It will explain how to test it step by step with pictures.

allrighty