BMW Repair: 1984 318i cold start question, jumper wire, cold start

Question
Hi,

thanks for the quick reply.  I have done what you asked.  I noticed that there are 3 valves on the thermostat.  I looked at one to check if there is a 12V.. There was for a brief second and none.  I'm assuming that is the thermo switch you are talking about.  Not that I have confirmed that is working.  I'm left with that plug for the injector that connects to the manifold.  That one still does not give any voltage when i turn the ignition key.

Any ideas where I can check next?

Thanks

Peter
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Followup To

Question -
Hi,

I am having problems with starting an 1984 318i when it's cold.  Cranks forever and doesn't not turn.  I have already replaced the injectors and the cold start valve.  The Spark plugs are ok because once i force the car to start externally (described below) then the car runs perfectly.

The interesting thing is this.  If I get an external power supply (12V) and connect it to a plug that is suppose to shoot fuel to the Manifold, I can start the car then; but not when it's left alone.  In Other words, i basically have to trigger that value to work.

I'm assuming it is the Jetronic ECU, but i'm not certain and would like to try other methods before looking for an ECU.

I would also like to know what kind of valve that is that is screwed onto the top of the manifold.  looks similar to some injector.

Any advice is appreciated.

Thanks in advance.

Answer -
Peter,
 That valve on top of the manifold that looks like and injector, IS an injector.  In fact its called the "cold start injector".  Something tells me that if you put 12V to this injector, and it started the car fine, then that's your problem.  
 So now you need to see why that's a problem.  Obviously you know that the injector is working, as when you run a jumper wire to it, it works.  So you need to test the wires running to this cold start, and see if they have 12V in them.  If they do not, I would check the thermo-time switch that is located in the thermostat housing.  This is a little sensor that tells the ECU when the engine is up to temp.  It could be telling the ECU that everything is warmed up, when the car is cold.  That would turn the cold-start injector off.

  It looks like you've done the brunt of the work here, finish up by checking the sensors and wiring.

 Good luck,
 Josh

Answer
Peter, this is the sensor I was referring to:

(see #4 on this website)

http://www.realoem.com/bmw/showparts.do?model=1384&mospid=47315&btnr=11_0683&hg=


 You can test it with an Ohm Meter, and it should have a certain value when cold, and a certain value when warmed.  This value is obviously wrong since it's telling the cold start injector NOT to work.

 Good luck,
 Josh.