i have a 740 volvo. 2.3 ltr standard petrol engine. It starts up ok every time while the engine is cold , after driving it for about 4 miles or so, temp guage reads normal, if i have to slow down to stop for traffic etc when changing down the gearbox with no accelaration used to revs drop off to zero and the car stalls. It starts up again at the flick of the key but will continue to cut out untill i have driven for about 8 miles or so then it will tick over ok.