knocking????

ok i have an 89 ford escort gt ith a 1.9ho how come everytime i change gears it knocks/pingsits a manual

if you get detonation you are either running too lean or use octane too low.

Your timing could be off 1 or 2 degrees. I say that 'cause if it was off more than that it would run worse than that. You engine should be advanced about 2 degrees to compensate for wear considering it's an 89.

Could be many things, this is just an idea.