QX4 stalling at idle while warming up

[bpivr]

I have a 1998 QX4 with 98K miles. I recently had a couple of oil leaks fixed and went ahead and got a new timing belt, water pump, and oil/filter change. Ever since I have had the car back, it has run fine except for the period where the temperature is rising from just below the temp gauge's "C" line to just above. Car starts cold and revs at 1000-1200 rpm at idle. As it warms up, the idle goes to approx 750rpm. If I am stopped at a light, or stopped in traffic when the car transitions from cold to warm, the rpms begin to oscillate from approx around the 1000 mark and then die. It won't start for a minute or so - seems like it is flooded or something (no evidence, just a guess). The place that did the work has tried cleaning the throttle body, replacing the fuel filter and say they've cleaned the MAF sensor, but the car continues to stall out. After it's warmed up, it seems to be ok. Any thoughts on what to do would be greatly appreciated.

[ARKQX33V6]

Coolant temperature sensor when going will ddo this, check it out especially when it comes to operating temp.

[bpivr]

Thanks - I'll check it out