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'83 VW Rabbit CIS hard cold start

In warm weather or whenever the engine is already warm - it starts right away and runs excellent. In cold weather (below about 40 degrees F) it is hard to start. After about 6 trys it will start. What is the most probably cause - cold start valve, aux air regulator, thermo-time switch or what? What is trouble shooting sequence? I would like to start with the most probable cause. I once had a Datsun 280ZX with a similar problem. I hot wired the cold start valve to the battery (with inline fuse) with a spring loaded off button on the dash. During a cold start I would just hold the button in for a few seconds while cranking and it would immediately start. That worked for a few years until I sold the car. Would the same procedure work OK in this Rabbit? Thanks Gene

Reply to
Gene
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could be any or all of the above... my guess and it is just a guess is the cold start injector. but if you haven't by now, investing in a Bentley manual for this car is an invaluable resource. I personally am rather fond of the CIS as it generally doesn't give that many problems although you are obviously having one of those exceptions :)

nate

Reply to
N8N

Most likely the cold start injector at the end of intake rail. I had a

1988 Jetta with CIS. Similar behavior to yours.

This used to be an online copy of the Bentley manual(s), but appears to be gone now...

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Still a lot of good info there.

You could probably hot wire the injector and not have any problems. Check the connector for it first. Also check the connections to your coil. They may be borderline, and under harder starting conditions may not be sufficient to get a good spark.

JW

Reply to
cyberzl1

Thanks to Nate & JW for their input. I pulled the electrical connector from the cold start valve, put a volt meter across the contacts. No voltage while cranking!! Apparently the cold start valve is not working because it's getting no "juice." So - no what, what do I check next?? I guess I could "hot wire" the cold start valve (as I did my old Datsun) to energize just during cranking. Thanks Gene

Reply to
Gene

I *think* it is only controlled by the thermo-time switch; however, this is where the Bentley starts to become really helpful, as my memory is not so good.

nate

Gene wrote:

Reply to
N8N

Thanks to all that responded. CIS parts are very expensive new -- and there aren't many Rabbits in junk yards any more. To solve the problem I hot wired the cold start valve to the battery (inline fuse) with a spring loaded to off button (like a door bell button) on the dash. During a cold start I hold the button in for 2 seconds maximum while cranking and it immediately starts. Problem solved. Gene

Reply to
Gene

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