1991 Toyota Corolla Wont run right

There are a lot of variables there. To start, the sparkplugs need to be replaced. Once plugs become fouled with oil, they generally need to be replaced. Second, there is oil seeping into the plug well or into the cylinder itself. When you had the car running, was there smoke coming out of the exhaust? If so, was it greyish/blue and smell like burnt oil? If the spark plugs are installed in through wells in the valve cover, the seals that keep oil out of the, "well" that the spark plug goes into could be the reason the plugs are coming out covered in oil.

Also, how uch gas was in the car when you left it sitting?

Has the fuel filter been replaced in the last 20-30,000 miles? Or within the last 2 years?
How often has it sat for extended periods of time?

Do you live in a cold climate? Has the Anti_Freeze been serviced on a regular basis?

Get back to me with that information and I will try to help you figure out what is going on.

One other thing is that when you park a car for longer than 30 days, the gasoline will break down, unless you use a fuel stabilizer.

He brings up a good point. Fuel turns into a varnish like goo especiallyif your gas tank is low, in a high humidty area or the weather is very cold or very hot.
Fuel stabilizers will by you time. Most people think tht running a car every so often in storge is good, but it can actually make things worse.
Another gs addidtive that I personally run in my Integra is BG44K fuel injector cleaner.
Irun a can every 6000 to 9000 miles. I also do it right before I change the oil because it does such a good job, it tends to make your oil dirty.
If you are in a situation where the can inthe tank is not enough, BG offers a direct manifold tretment that really cleans out the entire intake system.
I believe there are links on the site to find it.

Glad I could help you out.
Definately put some fresh gas inthe tank and run a can of BG44K and then change the oil.

If the plugs continue to oil foul and you get the burnt oil exhaust smoke, you probably have either leaky valve stem seals or a leaking head gasket.

Hope it is something simple. Good luckand let me know if I can help any more.