I have a 1991 Honda Civic (195k miles, 4spd manual) which generally runs fine with one exception. There are many hills around the area I live (Oakland, CA). After making it to the bottom of one, the car hesitates, sputters and generally drives poorly, especially starting off from a traffic light or stop sign. The poor running generally lasts about a minute or so before clearing up. If, in an attempt to make things better, I give the car a lot of gas, I get a big cloud of gray smoke out of the tail pipe. Any ideas what could be causing this? I figured this was fuel related and recently changed the fuel filter, but that did not help.
Many possibilities for a rich running engine. You need to start with the diagnostic chart and work down. Some possibilities: dirty air filter, too high fuel pressure, leaking/dripping fuel injectors, engine control system NOT going into closed loop operation, fouled spark plugs, or poor spark plug wires, and on down the diagnostic list.