I am working on my 1980 245 DL B21F, tracking down vacuum leaks, etc. I also have some cold start problems. Yesterday, I pulled the cold start injector - no fuel squirting out when I try to start the car, and I did not feel or hear the solenoid in the injector shift. I disconnected the injector from the engine harness and tested for voltage at the harness connector while cranking the motor. I get a signal between 6-7 VDC when I first start spinning the motor. After about 8-10 seconds, the voltage drops to between 3-4 VDC.

I pulsed the injector with +12 VDC in my hand and could feel and hear the solenoid shift. I hooked the injector back up to the engine harness, tried it again and it still doesn't respond.

I know that the thermal time switch is in the control loop - does it make and break common, or +12 VDC? What minimum potential is required to activate the cold start injector and what is the correct potential?

While I am at it, I intend to pull the auxilliary air valve and test its function. I have the same questions regarding the correct potential for that valve - if I apply that voltage across it, I should be able to see the bimetallic spring force the valve closed as it heats.