I am probably not the best person to go to regarding engine
and
injection timing, but since I have had so much difficulty with the
matter, I
have had to educate myself a little more than I ever wanted to.
Please read
this entire write-up before you get started in case you have any
questions,
and so that you know what you are getting into. CAUTION: The Bosch
5-cylinder pumps can be somewhat sensitive. Dropping the pump or
jolting it
too harshly can cause the rack to become misplaced inside the pump,
and you
will have to have it serviced to fix this... IT IS NOT CHEAP! That
being
said...
First thing's first: Pull the valve cover. I find that unscrewing the
three
10 mm bolts that hold in the cruise control actuator and moving it over
allows for easy replacement of the valve cover, for what it's worth.
Then
remove the fan blad and shroud from the bay by means of the four 10mm
nuts
that hold the fan in place. This will give you enough "swinging" room
for
turning the engine over by hand. Use a 27mm socket (a 1-1/8" works,
also)
on a small extension, 1/2" drive for turning the crank over by hand,
and
never go backwards. OK, this is all familiar from the valve adjustment
routine.
To pull the pump, remove all lines attached. There is one fuel line
banjo
bolt on the block-side of the pump, one fuel line banjo bolt on the
fender-side, and oil-feed line on the fender-side, and the fuel suply
that
goes to the priming pump and then from the pump to the main filter. I
usually leave the two that run from the filter attached to the pump,
and
just removing them from the filter block. Remove the oil-feed from the
pump, and this will allow easy access to the first nut you will
remove. It
is a 13mm, and there are three of them. The bottom is the easiest, I
think.
Just lay barely under the front of the car, reach your hand up there
with a
gear wrench, and feel for it. It's easy. To get to the top one, I
use a
13mm deep-wall on a 6-inch extension on a U-joint on a 3/8" drive
socket
wrench. It's not to tough. And the middle one (blocked earlier by the
oil-feed) can only be had by an open-ended wrench.
The final attachment is held in the back. It is a royal PITA to get
to, and
I have made a mock-up replacement. You will almost HAVE to use a gear
wrench for it (it makes life a LOT easier). Once that is off, go
under the
car, and remove the support bracket that mounts to the block at the
rear of
the pump (held on by two 13mm bolts). Once all of this stuff is
disconnected, you can remove the pump with the filter housing in place
by
sliding it straight back and upwards at the same time. I have heard
it is
sometimes necessary to remove the rack dampener pin, but I have never
had to
do so, and I have done this job probably around 11 or 12 times.
Once the pump is out, you will need to put your new one in. Crank the
engine over many times by hand to get everything "settled". I doubt
this
does anything at all, but it's a mental thing for me (OK, so I'm crazy
;-).
Look on the cam shaft near the front of the engine where it slides
through
the first bearing mount. You will see a tick mark. Turn the engine
over
until the stationary tick mark and the mobile tick mark are lined up.
Your
harmonic balancer should read at 0* TDC. Crank the engine around
again,
passing TDC once (that will be the exhaust stroke), and stop at 24*
BEFORE
TDC the second time. The tick mark on the cam should be just shy of
reaching the TDC marker.
With the engine at this time setting, you will shoot the pump in.
Take a
3/4" wrench for socket wrench, and as you look upon the nut on the
front of
the injection pump, turn it clockwise, making several resolutions.
Then
crank it, and again, only clockwise, until the spot with a missing
tooth
lines up with the dash mark that is set about 15* behind 12:00. It is
easy
for it to move out of time, so you must be gentle with the
reinstallation.
Slide the collar that came off out of the engine with the pump over the
sprocket on the pump. There is no special way to do this... just
slide it
on without turning anything. Piece of cake. Then, gently lower the
pump
into the engine, frontside going down first at an angle, and let it
slide
into place. Tighten it down at a random position with the nuts (NOT
the
rear bolt) and connect the feed lines. Pump the hand-priming pump to
hell,
and vent off your fuel filter so that there is NO more air in the
system.
Crank the engine over by hand, and see if fuel comes out of the feed
lines.
If it does, great. If not, reconnect your fuel injection lines, and
pull
the socket wrench of the engine. Then, disconnect your glow plug
relay, go
in your car, and hit the starter a few times to build some pressure in
the
lines without starting the engine. Go remove the line #1 injection
line,
and soak up the diesel in the port with the corner of a shop rag, being
careful not to leave lint or anything behind. Then crank the engine
over by
hand, monitoring that first port. When you just BARELY start to see
fuel
well up in it, stop. Look at your degree marker. If it is at 24*
BTDC,
then your perfect, though I hear running at 26* can offer a little more
low-end power. To advance, loosen the three nuts, and tilt the pump
AWAY
from the block with a cheater bar of some sort. Two people help this
to be
done a little more easily, as one can hold the cheater bar in place
while
the other tightens the pump. The lines will act as a memory-spring
that can
be a pain to deal with. If you want, remove all the lines (which is
what I
prefer).
Once in time, tighten the three nuts down nice a snug, and reinstall
the
bracket that supports the rear of the pump. Instead of using the
original
13mm bolt that goes throught the mount and holds the pump, I epoxied
some
washers to a 1/4"x1" bolt and slide it throught the hole. Then just
tighten
down a lock-nut on the front side of the hole. It will take you about
15
minutes of dropping the bolt to do it right, but I have yet to figure
out
how to put the original 13mm back in hole. Connect the spring from the
support bracket to the small hole in the arm on the block-side rear of
the
pump (mechanic's fingers make it a piece of cake... without them it is
nearly impossible, I think), and then reconnect your linkage. Check
your
timing again, and if it is spot on, put everything back in place,
including
your cruise control actuator, tighten the injection lines tight so they
don't leak, but not so tight that they strip (that would suck!) and
reinstall the fan blade and shroud. Jam the manual kill switch, and
crank
the start until oil pressure reads (the pump will then have oil
circulating
in it). Un-jam the kill (I just wedge the handle of a screw driver in
it),
and start her up.
First time I did this job, it took me about three hours. It now
averages
about an hour. Having a very clean engine always makes things much
easier,
less time-consuming, and overall more enjoyable.
Trace Cody