Hello, I am new to this site and I would like some advice on a problem I am having with my 2005 Dodge Caravan SE 3.3litre. When driving at aprox 50mph (80 k/hr) the engine seems to cut out. The rpm is aprox 1500. If I drive faster, eg 70mph the engine seems to be smooth with no cutting out. Also slower speed is fine. If I am in park and rev the engine to 1500rpm it is smooth with no sign of cutting out. If I put it in drive and have the breaks on and rev the engine to 1500rpm there is also no sign of the engine cutting out. Any advice would be much appreciated.

Thanks H