Maybe a dumb question but I bought a heavily used truck a week or so ago with a v8 in it(05 gmc). When I got it the idle rpm was around 650rpm and there was an odd ticking noise from the bottom of the engine.

The truck came with new spark plugs that weren’t installed so last night I pulled it into my garage and decided to inspect a plug to see how they are, when I pulled the spark plug wire it was extremely loose and basically not even on and came off right away. I pulled a plug did my inspection then put it back in with the plug wire in really tight and connected. Well since then my idle rpm is now 850 ish and that tick noise is gone and seems to be running smoother so I’m assume the plug wire was loose and not sending a spark?