I have a 2 years old car designed based on Peugeot 405 and the car has gone 35000 km so far. Last week I was on the road for about 2500 km. The first 300 km the car was fine, the AC was on as well. It was 45 degree celcius outside. Then suddenly I felt the engine lost its power and the car’s speed reduced and the electricity of car went of. I restarted the car and it was okay immediately and I went for 10 more kilometers and it stalled again. I restarted this time after 10 minutes and It brought me to a big city (80 km) without stalling but again in the traffic of that city it started losing electricity every now and then. I showed the car to a mechanics and he changed the double relay on my car. He also checked my battery and It was 100% fine. Then I continued my trip for more than 1000 km without any problem (I went to the mountains part of country which was 20 degrees cooler in the afternoon). Uphill and downhill was okay and no problem. In the way back home, again in the hot summer, the car started stalling every 40 to 50 kilometers and after getting cool it was working again.
Another mechanics checked my car and he said I have to replace the fuel pump which I did.
However, this makes me feel worry when overtaking with the car. Still when I turn the AC on the car loses a bit of it’s power somehow that in the first gear I feel it is going to stall again if I do not press the gas pedal enough. what is wrong with the car in your opinion? MAP sensor? ECU? Electricity cables? Coils? Spark plugs? what else?
I have done the following before the trip: the spark plugs gap changed to 0.75 from 0.9 since it was mentioned in the manual of the engine. During the installation of sparks one of them felt into the ground but it looked like fine. Besides, the mechanics cleaned the stopper of the engine before the trip and reset the ECU afterwards. I was using a GPS also during the journey connected to the car.
Thanks in advance everybody.