Tuning injector mechanical governor response - Stanadyne type on generators MEP-005+

[bimota]

Question: how to tune the mechanical governor build into the injection pumps on the various generators - MEP-004, MEP-004 and MEP-006 among others I'd expect.

Under load the weight move slower and the injection pump has two mechanism to hold RPM - the weighted mechanical governor and the auto advance mechanism. These work in concert is my understanding to keep the engine as close to the setting (1800rpm) as possible under load changes.

So have gotten comfortable taking these Standyne DB2 injection pumps apart for cleaning and replacing some leaking seals etc. We do not rebuild per say - just get them working, cleaned up and leak repaired. So they all work well now but we are unsure how to adjust the governor function to optimal performance.

Anyone know this process? We have the TMs and the Stanadyne manual but did not see step by step testing or adjustment process - assume an MEP-005 as the typical unit to be tuned.

 

[Munchies]

The TM wants you to put it on a pump bench and set the droop via fuel volume (mm3)
(j) Perform speed droop adjustment as follows: (See table 3-1.)
1. At 900 rpm and wide open throttle, adjust high idle screw temporarily for 15-20 mm3 delivery per
stroke.
2. Raise pump speed to 927 rpm and turn the droop adjustment cap assembly clockwise as viewed
from the transfer pump end of injection pump to obtain a delivery of 15-20 mm3 per stroke.
3. Lower pump speed to 900 rpm and check full load delivery rate. If 58-59 mm3 delivery rate is
not realized, repeat steps 1. and 2. above until 58-59 mm3 is obtained.
4. When step 3. requirements are met, lock the high idle adjusting screw.
5. If fuel pump is to be used for 400 HZ application, reset high idle speed screw to 1,125 rpm.
(k) Check delivery at 750 rpm. If delivery is not 55-58 mm3 per stroke, repeat step (j) above until it is.
(1) Raise pump speed to 950 rpm and check for a delivery rate of 5 mm3 maximum.
(m) Lower pump speed to 900 rpm and reenergize the solenoid. Check for 5 mm3 maximum delivery
rate.
At the same speed, energize the solenoid and check the manual shutoff for the same delivery rate
of 5 mm3 maximum.
3-64
ARMY TM 9-6115-464-34
AIR FORCE TO 35C2-3-445-2
NAVY NAVFAC P-8-624-34
(o) At a pump speed of 200 rpm, repeat steps and (o). Delivery shall be 2 mm3 maximum.
(p) Check minimum cranking speed delivery as follows:
1. Check transfer pump for 8 psig minimum and close the shutoff valve to gauge.
2. Check for 35 mm3 per stroke, minimum, at 75 rpm.
(q) Remove pump from test stand.
g. Installation.
(1) Remove fuel injector nozzle from No. 1 cylinder.
(2) Turn the engine over until the 20 degree before top dead center (BTDC) mark on the flywheel is lined
up with the timing mark on the flywheel housing, and No. 1 cylinder is on compression stroke.
(3) Remove the timing hole cover on the injection pump and rotate the pump shaft until the timing marks
line up.
NOTE
The pump shaft should never be turned backwards to align internal timing marks.
(4) Install pump on engine and install attaching hardware.
(5) Recheck flywheel timing marks then rotate the fuel pump body until the pump timing marks are
exactly in line. Tighten pump attaching nuts to 35 to 40 ft-lb.
NOTE
After fuel injection pump is installed, rotate engine 180 degrees backwards. Then
rotate engine in correct rotation until 20° BTD timing marks on the flywheel appears in
flywheel timing hole and recheck pump timing marks.
(6) Install pump timing hole cover.
(7) Install fuel Injection lines.
NOTE
New injection pumps received from supply have a high idle adjustment of 1,860 rpm for
60 HZ applications. Installation on 400 HZ generator sets requires resetting the high
idle adjustment screw (29, figure 3-21 ) to 2,250 rpm Adjustment is accomplished using
an engine speed tachometer, with actuator linkage (6, figure 3-20) disconnected, the
shutoff lever (21, figure 3-21 ) in the on-fuel condition, then manually operating the
throttle lever (35, figure 3-21 ) against high idle sto

 

[rustystud]

Good write up Munchies !

 

[bimota]

Good except it won't help us without a pump bench - which of course none of us have. Thanks Munchies but is there not an installed way to test the response of the governor to loads applied to the generator? Many of us do have load testers so I can vary load from 12-50kw and I can measure frequency with a digital meter - what I don't have is a process to adjust the governor to make the generator respond the way it is supposed to.

Thanks,

 

[flydude92]

This may work.

c. For Class 2 (Utility) Sets (Real Power), adjust
governor droop as follows:
(1) Start and run engine until it reaches operating
temperature.
(2) With rated (30 kw) load applied and the engine
operating at rated speed, droop may be determined
by removing load and noting no-load frequency.
(3) Adjust the knurled knob (15,Figure 3-1
located at the rear of the fuel pump, until the difference
in frequency between no-load and full load is 3 percent.
Note the increase of hertz when load is removed. At 60
Hz, droop should be 1.8 Hz, and at 400 Hz, droop
should be 12.0 Hz.

This is part of paragraph 7-10. PARALLEL OPERATION PROVISIONS (TM 5-6115-465-34)

I used this to adjust my 005 last year.