I have a 92 civic hatch with 95 gsr motor swap. There seems to be a recurring problem with the fuel. Ever since I put the motor in about a year and half ago, it has been running rich. All parts seem to be working to spec and I have all the right parts as well. I just can't seem to figure out where the enrichment problem is occuring from. This is bad as you could imagine because not only are my ports about seized up, but it keeps coating my spark plugs and there is massive carbon buildup on my pistons. I need to get this problem fixed and suggestions would help. Could it be a faulty fpr? If so, how can I tell. Also, could it be the injectors? How can I tell?

Recently:

The car has been running fine except for running rich. The car has its power and everything works well except since about a week ago. One day back from work, the car started to hesitate. Usually, this would be the problem if you have a bad tps sensor, but I had just replaced it and it was working fine. Then, the very next day, I get in, ready to go to work, and as I am driving down my road, it not only hesitates really really bad, but now it backfires and will hardly get up when I press the gas. I am assuming its the spark plugs and that they are coated again and need to be replaced. I will not know until tonight when I open it up to try and fix it. Other suggestions my friends gave me were loose timing belt (stretched) or bad spark plug wires. I need help with this situation because I am stuck at the house until it is fixed.

Thanks,
Undrgrndhaqer