I drive a 1990 Audi 80 b3 with 2.0-liter gasoline engine (I have no idea what the correct term is in English since it is not my native language, so please excuse me my mistakes).
Today I encountered a problem with my car, in the morning it started up just like usual, but after driving for like 5 minutes total, after I came back to the car from the shop it didn't want to start. It felt like it wanted to, but something was missing. I called a mechanic and he said that there could be a problem with the fuel pump or the spark timing. I came back to try and start it after a couple of hours and it started with no problems, but as I started driving the car was struggling to accelerate and I had to keep it on high RPM to get it home.
There seem to be no problems when the car is idling. At home, I pulled out the spark plugs and the 1st and 3rd spark plugs (counting from the timing belt) were blackened. I put in different spark plugs to check if maybe they needed replacement, but regardless, the blackened spark plugs were always in the 1st and 3rd cylinders. And the fuel pump seems to be working just fine.
Also, the RPMs go up just fine if I give it gas slowly, but if you do it a bit quicker, the engine just starts shutting down.
The question is - what could be the cause of this and how do I fix it?
I would really appreciate the help for this because I need the car back on the road in like 18 hours.