Hey, the head of my rover is different from the block and i found this number on the engine block, can this identify my engine or what it is?

Sounds like the coolant temperature sensor to me: https://rimmerbros.com/Item--i-MEK100061 If the sensor has failed, the ECU uses a default setting that will allow the car to run without overfuelling, but it will not enrich (choke) enough to start from cold. :welcome I've changed the sensor and sti...

Didn't know the ECU of 99 had that impact

Yes, this happands when i start the car on the next day or even when im not using for like 10 hrs
What is that sensor?

Hey, my car has a cold start issue, i've changed too many things and stil having the problem, i changed the spark plugs, spark cables , battery, injectors, belt distribution, filters ( fuel, oil, air), starter, butterfly valve i think thats it and already did a hole on fuel tank cap becouse it had v...