Adjusting Injection Pump For Begin of Delivery
Adjusting injection pump for begin of delivery (after checking begin of delivery)Special Tool:
Preparation for testing
Prior to adjusting begin of delivery, check begin of delivery of cylinder 1. Checking Injection Pump For Begin of Delivery
A. Preparation for adjustment
1 Set crankshaft in direction of rotation to 24° or 26° before TDC in compression stroke of first cylinder.
2 Loosen fastening nuts on injection pump flange and nut or screw on supporting bracket.
Attention! On engine 617 in model 115.1 use self-offset 13 mm box wrench for loosening and tightening front fastening nuts.
B. Adjusting according to high pressure-overflow method
1 Unscrew all injection lines.
2 Screw pressure limiting valves (arrow) on pipe connections of injection pump.
Pressure limiting valves are required for protection of injection pump, e.g., when rotating bV means of starter.
3 Engage pump unit.
4 Swivel injection pump while watching fuel jet. As soon as fuel jet changes into a chain of drops (arrow) begin of delivery has been attained.
Nominal value: 24° or 26° before TOC.
Swivel direction of injection pump
Toward engine = earlier begin of delivery
Away from engine = later begin of delivery
Note: If adjusting possibilities are not enough, displace injection pump. Displacing Injection Pump (After Adjusting Begin of Delivery)
5 Repeat checkup of begin of delivery.
6 Disconnect pump unit.
7 Assemble injection system.
8 Vent injection system. Service and Repair Run engine and check all connections for leaks.
C. Adjusting according to low pressure-overflow method
1 Swivel injection pump until fuel at overflow pipe changes to drops. Formation of drops: One drop per second.
Attention! On MW- and M/RSF-injection pumps with mechanical governor, push regulating lever of injection pump to full load while measuring and pull vacuum hose from vacuum control unit.
Note: On pipe connections with relief choke (2), on M/RSF-injection pump identified by a ring groove on pipe connection (arrow), no full fuel jet will come out of overflow pipe. But the measuring accuracy will not be impaired.
Swivel direction of injection pump
Toward engine = earlier begin of delivery
Away from engine = later begin of delivery
Note: If adjusting possibilities are not enough, displace injection pump. Displacing Injection Pump (After Adjusting Begin of Delivery)
2 Attach injection pump.
3 Repeat checkup of begin of delivery.
4 Unscrew overflow pipe and pipe connection.
5 Mount pipe connection:
a) Engine 615, 616 with M-injection pump
6 Remove delivery valve carrier (6), check whether delivery valve (4) is freely rotating in delivery valve carrier (6).
7 Insert pressure valve carrier (6) with ring groove in downward direction.
8 Insert delivery valve (4), new copper sealing ring (5) and compression spring (3).
9 Check rubber sealing ring (2) for wear and replace, if required.
10 Slightly lubricate pipe connection (1) on threads and screw-in.
For perfect seat of copper sealing ring, tighten pipe connection as follows:
Tighten pipe connection to 30 Nm, slacken. Tighten once again to 30 Nm and slacken again.
Then tighten to 35 Nm.
11 Mount injection lines and clamping jaws and vent injection system. Service and Repair
12 Run engine and check all connections for leaks.
b) Engine 615, 616, 617 with MIRSF-iniection pump
Insert delivery valve (4), new copper sealing ring (5) and compression spring (3).
13 Remove delivery valve carrier (6). Check whether delivery valve (4) is freely moving in delivery valve carrier (6).
14 Insert delivery valve carrier (6) with ring groove in downward direction.
15 Insert delivery valve (4), new copper sealing ring (5) and compression spring (3).
16 Check rubber sealing ring (2) for wear and renew, if required.
17 Slightly lubricate pipe connection (1) on threads and screw-in.
To obtain a perfect seat of copper sealing ring (5) tighten pipe connection as follows:
Tighten pipe connection to 30 Nm and slacken. Tighten once again to 30 Nm and slacken again.
Then tighten to 35 Nm.
18 Mount injection lines and locking plate and vent injection system. Service and Repair
19 Check regulating linkage and adjust, if required.
20 Run engine and check all connections for leaks.
c) Engine 616, 617 with MW-inlection pump
Slightly lubricate pipe connection (1) on threads, screw in and tighten from 40 to 50 Nm in one step.
Attention! The copper sealing ring (5) is installed under pressure valve carrier (6) and need not be replaced.
Mount injection line and bleed injection system. Service and Repair
Check regulating linkage and adjust, if required.
Run engine and check all connections for leaks. If a pipe connection is leaking, install new pipe connection with annular groove. When installing a new pipe connection, renew copper sealing ring under pressure valve carrier.