I just replaced the sparkplugs in my 90 GEO STORM now its hard to start

If your car was running when you replaced the plugs you either have the plug wires crossed or you didn't set the gap on the plugs.

Sounds like a fuel injection problem. Oh 1990 wow that is not fuel injected. Check the firing order. Your wires may have burned up. !990 geo storm umm blue book value of nothing. Get a new car!

I have a 90 Storm and the problem may be with the fuel injectors (yes it is fuel injected!). It also could be with the Idle Air Control IAC sensor - that it right up there by the air intake.

These are nice cars with nice mileage. Maybe older, but I am not paying a monthly payment to a bank for a car that is sucking down gas. If you can fix it, that is the smart thing to do. Most of the problems you will see are easy enough to fix since you can already change the plugs. Just check the Storm forums for a lot of good information.