Hi there, my fiesta turbo has all of a sudden started to jolt about and hold back at low revs (like its running on kangaroo juice lol). But the worse thing is it only does it every now and then so its not just a standard fault i think.
I was wondering if it could be fueling or the ECU maybe???

 

Is it chipped ??, mine used to do this when the chip was working loose from the ECU. When it next starts just try tapping the chip.