2001 Impala starting problem

Hello, I just bought a 2001 Impala LS with the 3.4 V6.It has 75,000 miles. I like the car but I have been having a problem with it starting. After you run the car for more than an hour it does not like to start all the time. It will turn over for 3 to 4 seconds and supter then start. I took it to the dealer and they put a fuel pressure regulator in it. This still did not fix the problem still does the same thing. It starts up fine when cold though no problem. Most of the time on the first few turns. Could this be the fuel pump? No service lights on either. The car also has a rough idle that just started the other day. I did notice a drop in fuel mileage though from 31 to 25? Any suggestions?

could be the crank position sensor or even a faulty engine coolant temp sensor making it difficult to start when hot

I will look into those two things. When the car idles the temp will go up to 210 and stay there. Once you start driving again it cools down. This is in Wisconsin when it is negative 20 outside. Does this make sense. Would a crank position sensor come up on a computer scan?

the temp should gradually rise to 200 and stop. Even in extreme cold it shoud still do so if the T'stat is functioning correctly.

Crank sensor Q, it can, but do not rely on the ECM to tell you everything

This thread is interesting to me...

If you read my other post here from today I had a failure (I think) of the engine coolant temp sensor (ECT) causing the temp gauge to never move above the 140 mark but the engine fans are run constantly, even after turning the engine off... Now the car also doesn't start... It cranks, fires, RPM's surge to above 2500, then down, then the engine stumbles and dies... I'm going to replace the ECT tomorrow...

Think the bad ECT could be the cause of my off again and on again starting problem??

not really. Starting issue sounds more like a Fuel pressur regulator crapping out.

Already changed the FPR...

I changed the ECT sensor and thermostat today... The car is starting and running again but as soon as I start the car the radiator fans run and continue to run for about 3 minutes after shutting the engine off... The engine temp gauge never moves above minimum... Any ideas?