94' SL2 110,000MI PROBLEM

1994 Saturn Other

I got a 94' Saturn SL2 with 110,000 miles on it. The car was great until multiple problems occured. The car now overheats, gas mileaged went way down, hard to start, Spark plugs get fouled, black smoke comes out of the tailpipe. However once on the road driving it runs great. Saturn can't find the problem, so I have done some work myself. I have replaced the valve cover gasket hoping that would stop the spark plugs from fouling with oil. Also I just replaced the EGR valve hoping that would get rid of the overheating problem. I'm I missing something because the car is still hard to start. In order to start the car when I turn the key I have floor the gas peddle at the same time. Once the car starts the RPM gauge goes way up then down to 1,000 RPM, and the engine fan comes on. Please help me, I'm sure that will run great once this slight problem is over.
June 3, 2007.

I have seen a lot of problems with the engine coolant temperature sender that tells the pcm what the coolant temp is. But I can't believe Saturn would have overlooked this.

That wasn't much help. So you think it's the coolant temperature sensor. I changed that! I put the EGR valve in and the black smoke stopped, and so did the overheating. Now I have to focus on why this car is so hard to start, and when started the idle acts weird then sometimes stalls. Is it a possibility it might be the head gasket? I have no idea what else it can be.

Jun 5, 2007.
Well, Excuuuse me! I would have known that you changed the ECT how? Don't get me started on the EGR situation. I don't see any point in trying to help at this point, would you?