Car starts when cold, wont start after being fully warmed up. wtf?

[mikey060]

as the title states, my 180sx will only start when the engine is cold. it starts perfectly too. doesnt hesitate at all. however after i drive it enough to let it fully warm up and then i shut it off, it will not start up again. it will crank but will not start up. once i let it sit for 3-4 hours too fully cool down it will start up perfectly again. it is very consistant and hasnt once failed to not start after warmup. any ideas what this could be? the car is basically stock, i have changed the air filter, fuel pump and it has aftermarket exhaust/downpipe. please help give me some idea what it could be. i will be taking the car to nissan but if there are some little things i can try i would like to atleast try them. thanks

[weaksauce]

I HAVE THE SAME PROBLEM WITH MY 1998 MAXIMA. IT WILL START UP FINE IN THE MORNING BEFORE I GET IT WARMED UP . IT WILL NOT START WHEN I TURN IT OFF AFTER THAT. I DON'T EVEN GET A CRANKING SOUND. JUST A CLICK AND THE QUITE BUZZ WHICH I BELIEVE IS THE FUEL INJECTION. AFTER SEVERAL TRIES IF IM LUCKY IT MIGHT START BACK UP. BUT EVEN THAT DOESN'T SEEM TO WORK MUCH ANYMORE. SO I QUIT TRYING. I HAVE TAKEN OUT THE STARTER. AND BATTERY AND HAD IT CHECKED. THEY WERE GOOD. I DON'T HAVE A CLUE WHAT TO DO. I SPECULATE THAT ITS THE IGNITION COIL , DISTRUBUTOR OR A RELAY. .. BUT IM NO EXPERT. VERY CLOSE TO BRINGING IT IN THE LOCAL SHOP. BUT NOT REALLY LOOKING FORWARD TO BEING OVER CHARGED.

[IanS]

Hot start issues are often attributed to a failed coolant temperature sensor.

Check the voltages on your coolant temp sensor at hot then at cold, if the voltage does not change, replace the sensor.