I have a 99 Mercedes ml430 that cuts off while driving or a stop light and won't start again for about 30 mins. to an hour. No codes were present on the diagnostics check so what could this be?

SOURCE: 1993 Mercedes after a long drive, engine cuts off at red light

Check out the crankshaft position sensor

SOURCE: durango cuts off while driving

hi, sounds to me that either the fuel pump is going out or the fuel pump relay is acting up. the cheapest way to check the relay first by simply swaping the relay with another relay in the power distribution box under the hood (swap it with the A/C relay)

SOURCE: Engine cuts out and wont restart for maybe 20/30 minutes

honestly, I've not seen an alfa romeo here in the philippines but i think you problem is partly electrical and the electronic side of the car. something on your car is heating up so much that it cuts the power to the ignition once it has. it is a possibility that a damaged ignition coil or a faulty computer box(if your car has one) or the control system that regulates the spark distribution system or the injectors(if your car is fuel injected type).