Can anyone pin point a fault that is causing mounting garage costs with no resolve. Since last autumn my 2005 hijet 1.3 pickup starts up fine on idle, however, until it fully warms up the engine wants to stall and requires my foot to the floor while driving. It's feels an old fashioned car with a broken choke that won't up the revs till warm. The vehicle uses petrol and LPG but the fault occurs with both. I've been to a number of garages including a Piaggio main dealer who gave up. It's been at the last garage for over two months! The 3 pin coolant sensor, upstream lambda sensor and even ECU have been replaced at cost, yet still the problem persists!! Mechanic says that the ECU is flicking open the fuel injectors far too long causing flooding and black smoke. However, yesterday he told me he had discovered an additional secondary ECU attached to the vehicle that governs the LPG. When he unattached this LPG ECU the whole engine went dead, but re-coupling it then found the fuel flow had much improved to a lower level. Although improved the fuel is still rich and the overall problem remains. He had noticed the secondary LPG ECU had loosely taped wires. I'm desperate having been without wheels for so long and MOT now expired. Thanks. Chris.