NEED Help with my z and noone knows

[spcburkart]

I have a 91 300zx with 190000 miles on it. It is starting fine in the mornings and when its cooled down like about 4 hrs after its ran but seems like its flooding ( black smoke ) until it warms up it likes to run at higher rpms, at a constant speed it cuts out when you get in to it, it misses and bucks sometimes but when it will not start with the key you can push it off and it will and some days it runs fine but most days not . I have changed the fuel filter the mass air flow senser and the spark plugs someone please help n

[marty1mc]

Check your temp sensor and Throttle psition sensor.

[robomatic12]

Check the ECU for any codes, I agree with marty it does sound like a temperature sensor problem. Clean all of your underhood connectors, most will have a green corrosion buildup on them.

[spcburkart]

Ok temp senser worked thanks