manual cold start wiring

[Ferrolanoman]

I want to install an instant switch (press-release) to deliver 1-3 secs of fuel before cranking engine so that it'll start quickly, thus by-passing the CSV system. My question is: should I get the power from the + of the coil or what do those who've installed a similar device recommend as a safe and reliable power source.
Thanks in advance.
Stay safe.
Ric

[WRe]

Hi,
similar realizations work only when the starter cranks.
http://w113.eu/geschlossen/Optimierungen/1%20Sekunden%20Modul%20Mercedes%20Pagode%20W113.htm.
...WRe

[Ferrolanoman]

I'm not talking neither original factory nor aftermarket devices such as the one you reference (although it would be nice to have access to it and the accompanying English version). I propose to simply energize the cold start valve at the intake manifold with a 12v impulse for a few seconds (1-3) so that it sprays some fuel into the intake and thus facilitate quicker starting. I mean for the fuel to spray BEFORE cranking when the ignition is turned to the ON position. It's been done before by some of this Forum members and I wish to know where the 12v is derived.

[Tomnistuff]

I hooked my wire from the battery positive terminal to one side of a spring loaded push button normally-open contact switch under the left side of the dash (the right hand is used for the key), and from the other side of the switch to the solenoid on the intake manifold.  It works perfectly.
Tom Kizer

[wwheeler]

On my W111, I used to the power take off for the radio. Where you get the 12 V source, isn’t a big issue as it only draws a bit of power. The other lead goes to the solenoid as Tom says. I love it and will never take it off!

[Tomnistuff]

After much frustration trying to overcome some fault in the cold start circuit that blew #6 fuses and refused to function as intended even after having passed the TM diagnostic tests, I consider this a solution for those who don't trust Rube Goldberg devices and who yearn to be in control of their lives, although I would rather have it work as intended.  It does, however, serve as a good anti-theft device.
Tom Kizer

[lpeterssen]

Dear Ferro

For this project you mention, positive signal should be taken from the T50 terminal on your ignition tumbler switch as you want to activate this timed relay only when cranking your engine for a period of up to 3 seconds. 

So my advise is the following:

Buy a “Bosch or Hella timed on” relay on amazon. Will give the link later. And the connections should be this:

Terminal 85 will go to the cabin where you will place a switch connected one end to ground and the other to the cable which goes to terminal 85 of the timed relay. By this way the system will be activated only when the switch is on the on position.

Terminal 86 needs a positive signal to activate the relay, so as you want the relay to act only during cranking, this lead should go to terminal T50 on your ignition tumbler. If your car is automatic, this signal can also be found on the engine compartment where the neutral/parking safety switch is located.  The cable is purple in Colour.  On manual transmission cars, look at the two major cold start mechanism relays, the signal goes there also.

Terminal 30, is the positive lead that is switched to activate the CSV at the intake manifold.  This signal should be taken from a fused source only alive (powered) when the ignition switch is on the on position.  So I recommend to take that positive signal from the fuse no.3 on your main fuse box. Do not take positive from battery, is not safe......

Terminal 87 is the output of the timed relay. That output is a positive signal and should be connected to the positive side of the CSV SELENOID.  That valve has two terminals in some cars, to determine which is the positive side just make a continuity test between each pole and the ground. The terminal which gives continuity to ground should not be used. Use the other one.

This is the relay you should buy:

https://www.amazon.com/HELLA-996152131-0-900s-Delay-Control/dp/B003C508XO/ref=sr_1_1?dchild=1&keywords=Hella+timed+on+relay&qid=1589321249&sr=8-1

Regards
LP

Ps any further questii9ns write me a PM

[wwheeler]

The main point of this switch is to activate the CSV BEFORE the engine cranks, not during. Having fuel sitting in the manifold waiting for the engine to turn over allows for faster starts. This switch is totally manual and how long or short it injects, is up to the discretion of the driver. The reason this has come about is that certain parts of the injection system have worn and the mechanical nature of the cold start system is unable to cope and adjust for that. If everything were brand new and functioning as they should, it would not be much of an issue. But the parts are not new and this is an effective way to overcome wear and tear over the years. You can rebuild an injection pump, but it will never be as good as when it was truly brand new. 

Mercedes basically admitted that using mechanical devices to manage cold starting with a mechanical fuel injection system over a wide variety of conditions, was almost impossible at best. Just look at how many versions they had in the years from 1959 until 1971. I know the W128 Ponton 220SE had two versions in just two years ('59 and '60). Then the later fintails and Pagodas had at least three. And those were pretty major changes.   

[lpeterssen]

Good point.

[Ferrolanoman]

Thank you to all who've responded. In the interim I figured out that Fuse #3 is only there for use automatic transmission cars. Since mine is a 4-speed manual, although it came with a fuse in place, this terminal #3 is unused. It made sense to me that it would still have power to it, and a test light confirmed it. So, I now have installed on the lower dash left side an instant/momentary push button switch--power from #3 on one terminal and power to the cold start valve on the other. Works wonderfully well every time: 1) ignition key to ON, 2) push/hold down button switch for ~2 seconds, 3) release button, 4) turn ignition key to START, 5) engine cranks over and starts almost instantly. My car has NEVER started as quickly or willingly prior to this fix.

[wwheeler]

YAY! Nice job and enjoy!