38 0 77KB
1
SERVICE BULLETIN FUEL INJECTION PUMP
ECD 01-06 November, 2001
NEW PRODUCTS DENSO AUTHORIZED ECD SERVICE DEALER ONLY
SUBJECT: New ECD-V4 Type Pumps Pump Type
Part Number
Customer
Vehicle Model
Engine Type
Destination
ECD-V4
098000-033#
TOYOTA
LAND CRUISER 100
1HD-FTE
Europe
1. Introduction A new ECD-V4 type pump has been introduced for direct-injection engines. Compared to the conventional type, the most characteristic feature of this pump is the addition of the pre-stroke control. This control improves the drivability of the vehicle by improving the low-speed torque during start-offs.
QC0826
SERVICE DEPARTMENT 0111-IT-180 Printed in Japan QAANC-03
2
2. Pre-stroke Control With respect to the injection pumps in which the operating pressure increases year by year, the conventional ECD-V4 type has also been meeting the performance levels required by the engines, including high power, high torque, and low exhaust emissions. The pre-stroke control has recently been added in an effort to improve the operation performance of the vehicle at low speeds. Specifically, the SPV actuating current from the EDU is varied at low speeds, which effectively varies the pressure and regulates the injection volume.
Actuation pulse
Actuation current
ECU
Solenoid valve
EDU
SPV
Spill High pressure
Suction QC0827
Pump cam angle signal
0
1
2
3
with pre-stroke
Open
SPV
4
5
6
7
8
9
A
B
0
1
2
Pre-stroke volume controlled by SPV closed duration
Closed without pre-stroke
Injection volume controlled by SPV open duration
Cam
Injection pressure
Injection rate Pre-stroke volume QC0828
3
Reference: To address the needs for lowering the pressure in the idle-speed range and raising the pressure in the low-speed, high-load range, the pressure control achieved with the pre-stroke control effectively enhances the drivability of the vehicle in the low-speed range.
High-speed, high-load range
Low-speed, high-load range
Increased power through high pressure
Increased torque through high pressure
Injection volume
Vehicle start-off
Exhaust mode range Reduced emissions through high pressure
Idle-speed range Reduced noise through low pressure
Low-speed range
Engine speed QC0829