Hi Farky. Some initial thoughts. Is the RFW engine original, or a later replacement ? If the cambelt timing is slightly off (e.g. 1 tooth early or late) it will make the performance flat but unlikely to cause over-fuelling. A smell of petrol normally indicates a leak of raw fuel somewhere. If the engine is over fuelled (injector duration too long) the exhaust in pre-catalyst days would be sooty and smell of unburnt fuel, but if you have a catalyst I guess it would change matters (until it fails under the strain). Assuming you have no petrol leaks, it could be that the engine management unit "thinks" that there is more air entering the engine than is actually the case. The airflow is measured directly by the Mass Airflow Sensor and indirectly by the Manifold Absolute Pressure sensor. However, once you are off idle, the Air/Fuel ratio should be modified accourding to the signal from the Lambda Sensor in the exhaust, to keep the catalyst happy. Not sure what the small hose is from inlet manifold to MAF, normally the MAF just sits in the large air inlet trunking. Your engine type may well have been fitted to Peugeot cars of the same era, so this could be a source of information. One last thought, if the coolant temperature sensor is faulty the engine will "think" it is under cold start conditions and richen the mixture. The sensor is often separate from the one that drives the temperature gauge, so just because the gauge works it doesn't mean all is well.