Overheating

I have a 1993 Thunderbird 3.8 that over heats at idle and after about 20 miles of travel even if I'm all highway then the check engine light comes on. The water pump works fine when you hit gas at idle. Fan on too. No cracks in block or heads. Had them checked. Just got oil change. I need new spark plugs but that doesn't have anything to do with it, right? I don't know. I'm not loosing fluid. Just gets hotter than it should. Not too the point that it smokes or strands me. Just hotter than it should be. Does any of that make sense? Any help I can get will be appreciated...Laura

A new thermostat is cheap insurance and could easily be part or all of the cause. A good cooling system flush is always a good thing to do, as well. Get the codes pulled. There should be codes if the CEL comes on when this happens. A motor running lean runs hot which could be a result of malfunctioning o2's or other sensors.

I had my fuel injector replaced last month, So I'm thinking lean is not it. Flushed last month too. Had head gasket replaced then too. I will do the thermistat and flush again.
Thank you for your help...Laura

Is the radiator clear of any debris??? I would hose the radiator down and see what happens. From what I have experienced, a faulty thermostat or a clogged radiator would be the culprit for your problem.

Thanks, haven't driven it yet. Still need to change themostat. Radiator is clean and seems fine. I go through alot of gas fast so it may be lean, who knows. I am clueless. I have to have the car checked by someone that knows what their doing...Thanks guys...Laura