alright I have a 85 2.8 and in the morning or if I let my car sit for awhile my car is had to start it is not my battery because I already had that tested. I have replaced my fuel filter and someone told me about a cold start sensor, what does it do and would that be the problem.

Could you please describe the problem in more detail.

The car I had use to start then die, and run rough until it warmed up some. Is your problem simular to the one I just described.
The main problem was timing, and vaccum leaks.

The cold start sensor is a cold start injector. It was designed to kick in when a cold start happened, it often fails on our cars over time.

the problem is when I turn the ignition key to the crank position I will have to hold it there and sometimes I have to turn it 2 or 3 times when the engine has been sitting for awhile. But if it has been warmed up and only sitting for less than a hour it will crank right up.

I have a similar problem, except mine only starts up well if it's around freezing temp outside, or if it was running in the last 5-10 minutes. There's something in the ECM called "clear flood mode". If you put the gas pedal all the way to the floor and then try and start it, the ECM will actually not deliver fuel until the engine gets up to 600 RPM (meaning it started). Give this a try. If this helps your problem, then you may have a flooding problem that could be caused by injectors stuck open when the car is off (or a cold start valve that is stuck on?).

chack all of the ignition system as well. I have had 3 coils go bad on me in the last year, na devery single time, hard starting like you describe were the symptoms, along with a lack of acceleration/sputtering when you get on the gas.