Hello I have a mazda 323 year 1997 with 177000 km.
When I accelerate slowly the acceleration is completely discontinue until 3500 rpm. Happens more when the engine is cold. In this case it's difficult to mantain for example 2000 rpm. When I give full gas there is no problem. Had the same problem with a WV golf I.

One other thing I noticed is that one year ago when I got the car the acceleration speed increased after 4000 rpm, now when it reaches 4000 it gets less, then increases again to 6000 rpm. (Maximum is 7000)

The thirth problem is that often when the engine is cold I hear a little metallic noise (tictictic...) I thougt these are the valves.

Have you got any idea of what it can be?

Tanks a lot