Just finished fitting my new 2.0 zetec into my fiesta and started it up for the first time tonight. It started fine but keeps cutting out and spluttering at low revs. Took it up the road and seems to drive ok, but as soon as you let off the revs it cuts out
Could it be the petrol thats been sat in my tank for bout 3 months or probably something else? It has the rs1800 ECU in it, would this cause it to run badly as its now a 2.0?
Any help would be much appreciated