صمام التحكم بتوقيت الحقن معطل

The valve that advances or retards injection timing on a pump-controlled system, failed so timing cannot be varied. The engine runs at whatever timing the valve is stuck at, which is why it produces a performance complaint rather than a failure.

Stuck retarded gives poor cold starting, white smoke and a lack of power; stuck advanced gives a harsh knocking combustion and high combustion pressure. Neither points at a valve and both are commonly diagnosed as fuelling or mechanical wear. Check the circuit first and the valve's movement second — these valves block with debris and varnish as readily as they fail electrically, and the oil or fuel feeding them is usually implicated.