We have a fiat punto in with uneven idle, a tendency to try to stall or die while pulling away and flat spots, especially when cold but also when at running temp, no codes are present, coolant temp sensor is reading correct, lamda sensors are switching, the vehicle has new ecu and coil packs, all gas readings are fine, have carried out a smoke test to check for air leaks with none found, the only issue apparent is when connecting a vacuum gauge the vehicle appears to have poor vacuum.
Any help appreciated