Please Help 89 Ranger

Hello everyone. A friend of mine has a 89 Ranger. It sat for a few years and then he drove it down from Maryland to Florida. It ran perfectly. Then all of a sudden it started to run rough and now it dumps fuel intermittently out the exhaust. He had a mechanic do a full tune up plugs wires etc, and that didn't fix the problem. Has any one had this problem in the past? With the engine running, I tool a long metal tool and stuck it on the injectors to hear for clicks. The first one doesnt click but the rest do. I am assuming that injector is not turning on. Or maybe bad. I would like to do this right and find out what code the computer is giving, and then go from there. The engine light is on, but I don't know how to scan for the code. Can some one explain how to scan for the codes...?

Thanks

Chris

The injector you can't hear is stuck in the open position allowing fuel to flood out the combusion chamber and the exhaust. Replace that injector. It will throw a code when it leaks down.

I would suggest to change oil when the bad injector is changed.