I just bought a1999,it has been sitting for 6 yrs

When a carburetor sits it can develop up chunks of stuff to build up in in the fuel jets. You can clean them by taking them out and blowing with air compressor or using a fine piece of wire.

possible loose, bad or broken electrical contact that is cutting off current to vital part of the engine.

It has been parked for about 5 yrs ???? That's not good ! What kind of compression does the engine have ??? Did you drain the gas out of before letting it sit ?

I would say a bad Fuel Pump. It's in the gas tank. You can get a whole drop in setup for about $100 +- on ebay. U tube for installation, Be careful.

loose wire in ignition system.

It is possible you need a fuel pump or carb could be all gumed up from sitting around

it likley to be blocked jets,,,try tipping a drop of gas ie:10cc,,only into each plug hole then try starting it up, if it just bursts into life and cuts out again its all down to no gas getting to the engine,,,also engines do dry out if left standing around so the drop of gas will lube the pistons as well

Have you put a pressure gauge on and then drive to see if pressure drops. If it does it is likely the pump. Sometimes these problems lead to it being the computer.

If it has been sitting for 5 years, your fuel pump is most likely toast. They tend to rust up without use. You may also want to look at the inside of the gas tank and make sure it is not too rusty. It may need to be replaced as well.

ignition coil could be hold ur petal down to the floor after pumping it a few times let the gas get there see what happens