I have a '97 Maxima SE auto with 220,xxx miles, which runs/drives excellent, except for one thing. It starts right up if it has been sitting for a couple hours, but if I drive it enough to get warm it wants to die while I'm sitting at a red light or stop sign, and sometimes when I'm slow driving through a parking lot it acts up. When it dies, it sometimes takes a while to get it to start back. If I can catch when it starts to die I can stomp the gas to the floor. It will feel like its choking out for a second then it smooths out. If I'm driving on the HWY or interstate where the RPMs are above 2,000, it runs perfect. No stall or sputter. Also the car can sit all day and if the outside temp is HOT, above 85 degrees, it won't even turn over acts like there isn't a battery on the car. The CEL is not on and is showing NO CODES! I have changed both battery terminals, cleaned the crank and cam position sensors, MAF and I am about to loose it over this. PLEASE HELP!!! I've been searching threads all day and the only other things I can think of to try is to clean the IACV and TB. Any suggestions are greatly appreciated. Thanks a bunch.

 

something is not flowing freely, which is potentially the IACV and TB cause they both have its Idle job to keep the car on..if its clogged then air is not flowing freely. hence which is why it only dies in idle.

 

Sounds like you have two different problems. For the rough running, clean the TB and IACV. Otherwise I might guess a leaking injector, although I've never had one go bad myself.

When it doesn't start, do the dash lights come on? Have you the checked the battery connections and grounds?

 

I've replaced the battery and both terminals. The hard start has to be related because everything works, lights, starter etc... It will just turn over for a while like it is flooded out before it finally catches and starts then I have to rev the engine a couple times for the idle to smooth back out

 

Outside of any starter related problems, flooding can be a symptom of failing injector o-rings. Basically the plastic parts of the outer injector start to disintegrate over time and allow extra fuel to drain into the intake manifold.

Are you familiar with running a fuel line pressure test? One way to check for leaky injector o-rings is to insert a fuel pressure tester gauge in the fuel line between the fuel filter and the fuel rail and test for fuel pressure leak down.

I like to run a fuel pressure test to check for a failing fuel pressure regulator as well as leaking injector o-rings.

Another method is to check for a spark plug that is wet or with a blackened build up compared to other plugs. This usually goes with being able to smell un-burned fuel at the exhaust pipe when the hard to start condition occurs.

Another possibility is the Engine Coolant Temp Sensor (ECTS) could be sending the wrong information about the engine temperature to the ECU.