1990 mazda protege 323 fuel injector single over head cam

The only wrong thing is the idle at 1100-1300 rpm. The battery voltage looks okay, 14v when car engaged, but I got some voltage drops to 10-12v when I accelerated the engine (this happen 2 times) Near the coil there's a little box of 2x3cm with a connector connected and another smaller box with 1 cable and a negative. I noticed some gasoline smell but it was when the car was heating. I also checked the secondary coil resistance and I've read 13K Ohm when cold and 13.5 K Ohm when engine is hot. I've been for 30-40 min with the engine engaged at idle and nothing strange has happened. I bridge the LED with the resistor on the GND and TEN ports, I turn on the ignition (no engine start) and the LED turns on but nothing happens. Also I maybe be usefull for people with same problem, I don't know. I just want to be sure that people wants to give me help before describing my problem more detailed and what I've done during those 5 days. If the people of this forum doesn't want me here I understand, I'll leave. I've been for 5 days searching information about problem on the internet and I also have ask on specialised 323f forums but seems my car is not very popular and there's not much info but I've found that miata NA shares the same 1.8 dohc BP engine (or at least they're similar) and the problem my 323f has is common on miatas so I end up here guessing if I can request help from miata enthusiasts to solve the fault. After this I have to wait some minutes until the engine can be re ignited. It starts running rough, the idle begins to fluctuate and finally engine stalls.

The car has a problem when the engine reaches working temperature. My car is a mazda 323f gt 1.8i DOHC (BP engine code, without catalyst). First of all I have to say I do not own a miata.

1990 mazda protege 323 fuel injector single over head cam