Nissan Repair: 1997 Nissan Maxima Wont Start Warm (SOMETIMES), fuel pressure gauge, fuel pressure regulator

Question
Hello. I have a 1997 nissan maxima with 130,000 miles on it. It has been a reliable car except for this problem. When I start it cold, it always starts up no problem (summer or winter) I live in Wisconsin. I noticed that if I drove the car for a short period of time (long enough for the engine to be BETWEEN cold and fully hot)and then turned it off, SOMETIMES it will not restart immediately. If I let the engine cool back down,(temp needle on dash moves back to cold) It will start fine again. Seems to happen more often now that the outside temperature is getting cooler. I can tell you that I have replaced the fuel pump, and the fuel pressure regulator already thinking I was dealing with vaporlock.  These two components were appearantly not the proplem however. I have no fault codes set either to check. I dont think my injectors are leaking and flooding the engine....no gas smell when the engine cranks but wont start. When engine is running it runs fine. Is this a temperature sensor problem (coolent or air temp sensor)?  Can someone enlighten me as to where to look next?

Answer
Steve,

If the temperature sensor is defective the car will have a hard time starting when the engine is cold so I do not think this is your problem.  I would pull the plugs and look to see if there are any that are black with soot like an injector or two is hanging open.  You can check this by using a fuel pressure gauge and starting the car and then turning it off.  If the pressure drops off quickly you have a leaky injector or two.  Since the car starts after it cools off I think this is your problem.  Check the plugs and that will tell you which injectors are acting up.  A wrecking yard is a good source for used injectors.  Just do the same thing in checking them.  If a cylinder has a clean plug chances are that that injector is good.  Email me back with what you find.