Hi everyone,

I've been working on the cold start valve on my 1979 245DL, trying to get it to do what it's supposed to do (that is, help me start my engine!) I've compiled a list of testing procedures for the cold start valve in the CIS K-Jetronic system, based on the Haynes manual and the Bosch fuel injection book. I know that it's not complete and needs some serious editing, and I'd appreciate any advice y'all have to offer. One question: the ground wire that connects to the manifold next to the cold start valve--does that have to be connected in order for the CSV tests to work?

Thanks in advance,
Bob

Testing the Cold Start Valve (CSV)

1. Test to make sure the electrical connection to the CSV is actually sending a signal to the CSV. Detach the connector from the CSV, and after grounding one end of a test light, probe the connector while an assistant turns the starter--one of the terminals will light the tester, and should do so for no more than about 10 seconds. Any longer, and the CSV will be getting a signal to send fuel well after it's needed.

2. Test to see if the CSV leaking fuel. Described in the Haynes manual: take the CSV out, disconnect the electrical connecter, run the fuel pump. If it leaks more than one drop a minute, the CSV is junk and must be replaced (because if it's leaking that much under no load, think about how much will shoot out when you put your foot down!)

3. Test to see that the CSV is spraying in the right pattern. Described in other Brickboard posts: "Pull the CSV out of the manifold with the engine cold. Key on--jump fuse #5 to fuse #7 to make the fuel pump run. Then place the cold start injector in a small jar. Jump one injector terminal to ground and use your test lite to power up the other terminal from battery + . It should spray (an even, conical shape). If not, replace it.”

4. If the tests are unproductive (do not result in any spraying or drops), try some creativity: Start the engine with the CSV in it, then yank the electrical connector after 20-30 seconds. If the engine smoothes out, then the connector is sending the signal to the CSV well after it should—-the problem is electrical. If the engine continues to run rough, backfire, etc., then the CSV may be dropping fuel just from the pressure in the valve. It’s probably bad and needs to be replaced.

P.S. When conducting these tests, be sure to take all necessary precautions (especially in regards to the coil wire--you should probably ground that sucker for most of these tests)