Lachleaves1
Member
- Posts
- 20
- Location
- Anglesey
Wowsers!To far retarded bad hot starts. Static timing is set with .90 mm lift on cam. This gives slight advance for starting, the timing device in the pump is spring loaded so always returns to this setting when engine is cold or has been stopped for a time when hot and internal pressure has bled away. When engine is hot no cold start fuel is set by ECU so a retarded static can give hot starting problems. As the engine speed rises internal pump pressure increases until a pressure relief valve opens and returns fuel to the inlet side of the internal high pressure pump. The ECU receives a point of injection signal from the number four injector and uses this in conjunction with readings from the crank position sensor to modulate the timing solenoid, to control fuel pressure exerted on the timing device so that the point of injection remains at TDC no matter what the pump internal pressure is. Modulation at idle, warm engine, should be around 45% to 55% ideally 50%, the modulation solenoid can then go either way to control pressure on timing device subject to engine RPMs and internal fuel pressure. If the static timing is to far out either way it may not be able do this within it's range of operation, so the ECU will throw a modulation out of range fault.
Thanks.
