Help ! Engine cut out in traffic, low rev's

I drove my Megan 1.6 petrol coupe convertable 2005 plate to the local airport with no problems (10miles). On the way back i hit traffic. with all the stop-starting the engine just cut out. took a few attempts to get re-started and stay started. this happened at least 4 times. What i did notice though, on one occasion the rev's were sat at 600rpm. on the second/third attempt bunny hopped and died. Also on the final time i had to do this, i put my foot on the accelerator to try and keep the rev's up but nothing happened. eventually gave up and had to call out recovery as didn't think i could go any further. Today i can can start the car (takes about 30 sec's to kick in) but wary about driving it. Have replaced the MAP Sensor (3 weeks ago)

Help ! Engine cut out in traffic, low rev's