It started with the car shaking as if not all pistons were working. Then the engine became less and less powerful, and could not rev up to above 2,000 RPM while driving (but it could go to 3-4,000 RPM when parking). Idle RPM went down to below normal, and sounded like the motor wants to die any seconds. And the last phase: now I can only start it for a few seconds (500 RPM max and then it dies).

This happened during the days when I was replacing radio harness and installed new speakers but I guess it has nothing to do with the engine problem (first I thought a ground had been disturbed).

This is really annoying, because a bunch of new parts were installed a few months ago and the engine had been running great since then. These new parts: spark plugs, injectors, fuels lines to the injectors, ignition wire set, lambda probe, microswitch (idle), fuel accumulator, rebuilt warm-up regulator.

I have fuel in the tank and I checked the battery, it shows 12.2 Volts. Any ideas highly welcome...