I had a similar problem on a Berlingo 1.4 petrol 2001. Fluctuating revs and cutting out during warm-up and at idle speeds. And intermittent power choking during running, particularly mid-range on accelerating after cruising, such as through a speed limit area. It felt like a problem with fuel delivery or fuel/air mixture.
I checked the vacuum hosing and air filter, and changed the fuel filter: no difference.
Attention shifted to engine control. A mechanic tried a new inlet manifold air pressure (MAP) sensor. This seemed to make some difference to the warm-up and cut-out problems, but the mid-range choking persisted. And I now think the improvement was coincidence.
I kept trying: cleaning and checking sensor plugs and sockets, wiring, the ECU plugs. Throughout this period, the weather was warmish to warm, and the problem was mainly with the intermittent choking in mid-range; warm-up wasn't too bad.
Then on the first cold morning this autumn, the warm-up problem returned: wild rev fluctuations and cut-outs from the start. It had to be related to external air temperature. I pushed open the flap and brushed the inlet air temperature sensor with meths. Bingo. Total cure. The thing just had a layer of greasy grime, and the ECU had been unable to cope with its readings. Quite possibly, the MAP sensor had just needed a clean too.
Lesson: old cars have dirty inlet manifolds.
Edited by parcher on 15/09/2012 at 14:30
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