Nissan Repair: 95 Maxima stalls hard once after warming up, coolant temperature sensor, throttle position sensor

Question
I need help with a very puzzling problem.

I have a '95 Nissan Maxima with over 200k on it (has been a really great car) that recently started stalling while driving. Here's the situation: I start the car up in the morning to go to work - starts without issue and idles fine, also no problems with hesitation or acceleration. A few minutes down the road, after the engine comes up to operating temp, it still runs normally... until I come to a stop light or have to stop for traffic. About 75 % of the time at this first stoplight after warming up, the engine will just quit. No sputtering or prior warning. Starting it at this point is hard - I will then have to give it a LOT of gas and crank for about 20 seconds before it will start back up. When it comes back to life, I have to immediately take it up to 3000rpms (or it will die again) and VERY gently ease off on the gas to slowly lower my rpms back down to 1000, where I can shift back into gear (takes about a minute). If I drop too fast, it stalls and I have to start all over again - sometimes the rpms will jump around from 1500-2500 a little bit before settling down. This is all very frustrating when you are sitting in traffic.

Here's the kicker - once I get through this little episode, I can drive off normally without any problems for the rest of my commute. The car will act normally again, idle smooth, accelerate fine and sit at stoplights without any issues.

When I drive home in the evening, I have the same problem all over again.

One other piece of information - if I keep the RPMs up to at least 1500 the whole time I'm driving (shifting into neutral at stoplights) it won't stall.

The only code I'm pulling is the knock sensor, which shouldn't be causing this. I have checked out the coolant temperature sensor, MAF sensor, crankshaft position sensor, throttle position sensor and all seem to be working fine. I have changed the fuel filter and PCV valve. I replaced injectors about a year ago. My local mechanic and they couldn't get it to stall (figures).

My next step is checking fuel pressure. Any further guidence would be much appreciated!

Answer
Clint,

Change the knock sensor first.  I would also change the throttle position sensor as I feel that it is worn out.  With this many miles the contacts are gone and the failure is intermittent.  If you do not change the knock sensor the fuel economy will suffer since the computer retards the timing to keep the engine from pinging.