Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: rosch on June 27, 2022, 21:06:26

Title: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: rosch on June 27, 2022, 21:06:26
Just some helpful tricks ,some of you already  use or know :

1 . Linkage adjustment:
To adjust your linkage according the linkage tour your startingpoint is lining up the ball of the (central) control rod  with the  10 mm alignment bore on the intake manifold.  A simple tool that you probably have in  your toolbox anyway is a  drill bitholder. Guess what ? Most of them are exactly 10 mm in diameter and the "open" end will hold the ball nicely in position. ( see photo's)

2. Barometric compensator  simple  first function check :
You might know already  that the lenght between tip and the hexnut normally should be close to 21 mm.  To check if the BC is functioning at all you
can use a  piece of transparent tubing and a brake fluid change tool that can create a vacuum. Slide the tubing over the thread ( don't worry about a complete airtight seal )  and connect to your tool.  Creating some vacuum you will be able to see a slight  movement of the tip , giving you a first indication that your BC is working.

3. Tweaking the time function of the  TTS (Thermo time switch) :
A lot of starting problems are caused by the original TTS.  Sometimes the result of  the "aging ? " bi-metal strip /coil combination which take care of  the "time function "   I mean the one that is between the "G" connection and ground which has a resistance of about 30 Ohms. It operates the switch between "W" and ground.
This  "thermo coil " opens/ disconnects  the ground connection at connector "W" after  a predetermined time , related to ambient/engine temperature, and last but least-  the time you activate the starter.
What happens is when you engage the starter during relatively COLD conditions : "W"  is connected to ground  and power is applied to "G " and a current is flowing through the thermo coil part, which heats up ,causing the  bi- metallic strip to bend a little and thus disconnects ground from "W ". The CSV and solenoid on the injection pump -through te starting relay - lose power and switch off.
 If you like to experiment with this  heat-up time somewhat you might add extra resistance in the circuit to "G " 
Explanation : What this will do is reducing the amount of current  flowing through the "thermo coil part" , resulting in a slower warm-up time  and thus longer activation time  of the starting relay  (and thus CSV and  FIP starting solenoid) 
FYI : I used a Potentiometer  of 100 Ohms / 3 Watts which was at hand . It gives you ample range to play  around.
It might solve some cold start issues  you have....

Note : During WARM conditions ( read :  Hot /warm starts)  the time function  during starter engagements of the TTS is bypassed  !  This due to the fact that "W is already disconnected from ground by the higher engine temperature. The starting relay ( and CSV + FIP solenoid ) are now only  controlled by the 1 sec. relay  .

4 . Home made  WRD Oval shims :
Probably you already knoiw this solution.
For short duration testing puposes I used oval shims made of thin plastic packaging material to find the right thickness.. When the optmal thickness was achieved I replaced them with  a number oval shims cut from a beercan creating the same thichness. Advantage  : they are really thin so you can stack a couple  for exact thickness and -when cut  with a little effort-  are hardly visible from the outside when  applied.


Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: Pinder on June 27, 2022, 21:19:27
Great information and tips.
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: Benz Dr. on June 27, 2022, 21:28:26
Yur hired!
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: rosch on June 28, 2022, 06:06:18
Photo of the  Oval Shims.

The shims were made by using just  a   cutting knife and a home made hole punch
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: ctaylor738 on June 28, 2022, 12:07:11
Good stuff!

CT
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: wwheeler on June 28, 2022, 15:20:56
I like the idea of being able to tweak the TTS. I ended up installing a cabin switch to manually fire the TTS when and how much I think is needed. I have come to the conclusion that each person's car has worn just a bit differently and in a different climate over the 50 years, making a single solution not practical.

Having the ability to fine tune the amount of TTS activity makes sense. The one advantage of the manual switch however is that you fire it before the engine cranks and thus the fuel is in the manifold waiting. Super fast starts in the morning. But it is manual and quite uncivilized.  ;)
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: Raymond on September 06, 2023, 00:53:17
Okay.  I performed the test on the Cold Start relay and it is truly dead.  However, I also tested the wiper relay and it is working properly.  I plugged it into the cold start connector, and the CSV still does not trigger.  From this, should I surmise that the TTS is also dead? 
Should there is continuity between the lug on the CSV and ground even with the wire removed?
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: ja17 on September 06, 2023, 02:57:17
Switch the plugs between the two starting relays and see if your problem moves. The plugs should reach and the relays are exactly the same.
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: Raymond on September 06, 2023, 13:45:47
Hi Joe, I did that and the wiper relay didn't trigger the CSV.  I should have mentioned that I had removed the CSV and applied voltage and it activated the plunger. 
I opened the cold start relay on a bench and cleaned the points, but with voltage applied, nothing happened.  The wiper relay functioned properly. 
I'm confused that, with no wire connected to the CSV, the lug shows it is grounded but applying voltage to the lug triggers the plunger.  Is there a short somewhere?
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: ja17 on September 06, 2023, 14:30:01
Only the two start relays are identical. The wiper relay is a larger, squarer relay and it is different. One start relay is for the intake manifold valve, the other is for the injection pump solenoid. Since the intake solenoid is an electrical coil, one end of the coil is grounded. When current is switched on the coil is magnetized and activates. You will get a grounded reading on a non-energized solenoid. Keep your old bad relay, remove the cover and use it as a manual switch to activate or identify your starting aids. Just plug it in and manually press down on the relay to activate or identify!
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: Raymond on September 07, 2023, 00:54:30
I called the aft relay by the wrong name.  The forward relay is for the CSV.  Once, at a PUB at your place, you showed me the the plug swap, so that was the first thing I tried.  Then I took both relays out and bench tested them.  The CSV relay is dead.
 The injection relay works but it does not trigger the CSV.  So, I'm guessing that I'm either not getting voltage out of the plug, or there is a break in the line between the CSV relay and the CSV.  I'll try running those options down next.
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: Raymond on September 09, 2023, 00:49:38
I checked and cleaned the connections on the FI pump solenoids and TTS.  Then, for the heck of it, I took the CSV relay to the bench again.  This time, I bent the vertical arm that holds the bottom contact point to better align with the top contact.  Then applied voltage again and CLICK!  The thing worked this time.  The first time, there was a tiny visible spark.  I hit it several more times and it contacted with no visible spark, held for a couple of seconds, and released.  I put it back together and the car started right up.  I really don't think I did much.  I guess the relay was feeling neglected and wanted some attention.
Title: Re: Linkage , BC (Baro Compensator), TTS (Thermo time switch) helpful hints
Post by: ja17 on September 09, 2023, 03:43:29
Spray some electrical contact cleaner on the contacts and the plug connections next time for longer lasting results!