Thanks for that info; I have a 300SD that has that problems. I have not driven it in awhile because I acquired an 84 300D. The person I bought the 300SD from was told by an aftermarket Merc servicing business that the replacement of the shut-off solenoid would cost huge amounts of money, so he never fixed that problem of the 1st gear problem. I solved thw shut off solenoid problem with the help of this group several years ago..relatively easy fix.
The funny thing about the shut off solenoid is that it was sticking between off an on occasionally, and gave the impression starving the motor under full throttle, simulating a bad pump.
Thanks again
--------------------------------------------
On Sun, 5/1/16, 'Mark in Lakewood, CO' beeser750@q.com [diesel_mercedes] <diesel_mercedes@yahoogroups.com> wrote:
Subject: Re: [diesel_mercedes] Re: 1980 300SD will not turn over after short/long drive
To: "diesel mercedes" <diesel_mercedes@yahoogroups.com>
Date: Sunday, May 1, 2016, 2:15 PM
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First, determine
whether or not it is or is not starting in first. At a
stop, put the shift lever into "L"; this forces
the transmission into the first gear. Then accelerate.
If it seems to have better pick-up, then it is not
starting out in first when in "D".
The fix is probably in the vacuum
modulator. It's either malfunctioning, or it needs
adjusted. It's located on the right (passenger) side
of the transmission, just above the oil pan. It has a
vacuum line connected to it. You can check it by
connecting a hose to it, sucking on the hose, then putting
your tongue over the hose hole. If your tongue stays on
the hose without the hose falling off, then the modulator is
able to hold a vacuum.
To adjust it, you need to pinch the
two ends of the clip that holds the cover onto the modulator
body. The cover is the part that the vacuum hose connects
to, and will lift off (possibly with some difficulty) when
the clip is pinched. Under the cover is a sort of screw
driver that is held in place by slots in the modulator body.
Lift the "screwdriver" from the slots, and it
can be turned in or out. It would probably need to be
turned in. Turn it a half a turn at a time, then
reassemble the cover and do a test drive, until the car
starts out in first gear.
If that does not fix the problem,
then the valve body in the transmission has some sticky
spool valves. A fluid and filter change may (or may not)
restore it to proper operation.
Mark in Centennial, CO
From: "john public
brad_macaboy1234@yahoo.com [diesel_mercedes]"
<diesel_mercedes@yahoogroups.com>
To: "diesel mercedes"
<diesel_mercedes@yahoogroups.com>
Sent: Saturday, April 30, 2016 7:32:17
PM
Subject: Re: [diesel_mercedes] Re:
1980 300SD will not turn over after short/long drive
If it was starting out in
second gear, what is the fix?
It shouldn't be any
slower than the '81. At least, not by much. Is the
turbo spooling up? They can get gummed up if it's
not
driven hard enough.
Also, is
your starting out in first gear?. My '79 does, and
it
can easily keep up with any other 5-cylinder
SD.
The jumpy temp
guage is likely a spotty connection for the temperature
guage sending unit in the head.
Mark in Centennial,
CO'79 300SD
From:
"sandtaz@yahoo.com [diesel_mercedes]"
<diesel_mercedes@yahoogroups.com>
To: "diesel mercedes"
<diesel_mercedes@yahoogroups.com>
Sent: Friday, April 29, 2016 4:01:37
PM
Subject: [diesel_mercedes] Re:
1980 300SD will not turn over after short/long drive
Thanks to everyone for their comments, suggestions
and advice. Finally got around to replacing the neutral
safety switch (had 40 mph winds here in southern Arizona
the
last two days) and drove it to town and back (30 miles)
and
everything seems to be working fine. Shut it off two
different times and it started right up. I will take
Nate's advice and replace the solenoid. Nate, we
just
love the car and almost everything works, at least most
of
the time. Still have to tackle the jumping temp gauge,
right
side windows (motors work but do not operate the
regulator)
and the super slow acceleration. This car is much slower
than our 81 300SD. Cleaned the banjo bolt to the ALDI
valve
but not any better. At least it gives me something to do
with all my spare time. HA HA. Thanks again and you can
be
assured that I will have more questions/problems.
![IMG_1364[1].JPG](https://xa.yimg.com/kq/groups/215526/tn/251437207/name/IMG_1364%5B1%5D.jpg)
![IMG_1365[1].JPG](https://xa.yimg.com/kq/groups/215526/tn/1815465906/name/IMG_1365%5B1%5D.jpg)
