1978 Mazda 121 Pricing and Specs

The first thing to do is drive the car yourself and see if there’s a pattern to what’s happening. Until then, you have even less idea of what’s going on and a diagnosis is all but impossible at that point. You might find that the car is cutting out after a period of driving (maybe caused by a dirty fuel filter) or when the engine reaches a certain temperature (possibly a sick crank angle sensor).

I’d also recommend an electronic scan to see if any fault codes show up. These codes can be very specific and will often lead you straight to the root of the problem.

Any time a fuel-injected car can’t get fuel from the tank to the engine, the number one suspect is the electric fuel pump. These are often located inside the fuel tank and have a finite lifespan. And when they stop, they just stop. That’s it; no warning and only a new pump will get you going again.

However, it’s also worth checking that you don’t have a blocked fuel filter or a kinked fuel line or something equally random that is stopping the fuel getting to the engine. Nine times out of ten, however, the fuel pump will be the culprit.

From your description is appears that it could be repaired, but without actually seeing it I couldn't say how much it might cost. There are websites you can use to get a quote on-line and I'd suggest you do that. Google "bumper repairs".