93 Altima hard starting when warm

My Altima just started acting up last week. It was running fine and then one day after I was driving it, I got back in and tried to start it and I had to put my foot all the way done on the gas pedal for it to start. I replaced the wires, spark plugs, gas and air filter and nothing. Once it starts it runs fine. When the engine is cold it starts right away. But after an hour of driving it if I turn it off and then restart it I have to put my foot all the way down. Its like its starving for air. No engine light is on BUT I did a self diagonstic and it came up with the famous Knock sensor. Would that cause the hard starting after the car is warmed up. I know it retards and advances the timing but I thought that would cause the car to run funny not at start up. Any ideas??
Thanks
BM:banghead:

Do a search around here for 'oil in the distributor' problem.

I saw that a lot of us have the problem with the oil in the distributor but if that was my problem wouldnt it happen all the time not when the car gets warmed up? And the car will start when I put my foot all the way down on the gas.

no codes but you might want to try the coolant temp sensor anyway. Their cheap,When mine had probs that fixed it.

The coolant tempature sensor it was. Thanks a bunch!!

I take it back, it wasnt the coolant temp sensor. I will try changing the distributer