Ford puma engine problem

[simon mk2]

Can any one help?

I have a 1.7 ford puma and when it is underload at 1700 rpm the car jurkes as if you have changed gear to soon (only at this rpm anything under or over and not a problem).

I have checked the plugs and leads and they are clean.

is there any raeson for this and will it get worse?

any help will be great

Thanks Simon

[fiestaownersclub]

could be your lamda sesor at fault

[K1NGB1LLY]

could be the air flo meter or the air flo sensor,or mabee not enuf fuel but thats quite unlikely.
unless the fuel filter is cloged, whats the air filter like is it clean? more than likely be somthin silly mate at dont think it will be much to worry about, i had a 1.7 puma engine in my zetec-s and it was constantly abused a had it at the nurburgring back in may and it pounder 11 laps and drove home, i found it a solid little engine, a took it out to replace with anst170 thts givin be nothin but a sore head, i think ive been sold a busted engine,good luck mate :P