2002 Mazda 626 won't run for more than 3 seconds
 

Just stopped running in the middle of the road. Has been at dealership for 2 months and they still can't work out if it's electrical or fuel. Had ECU checked out by an auto electrician who could not find anything wrong with it. The fuel pump and fuel filter work and petrol is clean. Air flow meter, coil, crank angle sensor and cam sensor tested and all ok. Does anyone have any other suggestions?

Only thing I can think of is if someone plugged your exhaust, or if the ignition barrel has a loose connection? Could it possibly be a fuel pump not delivering enough fuel? Sorry I am new to this forum and only just inherited a Mazda 626 so don't have much hands on experience as yet.