Thermo time switch

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canada karl
Posts: 1058
Joined: Tue Jan 06, 2009 3:50 pm

Thermo time switch

Post by canada karl »

what are the signs if this switch fails or is failing in terms of hard starting?
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
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Mike W.
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Joined: Wed Aug 30, 2006 12:12 am
Location: Sonoma County

Re: Thermo time switch

Post by Mike W. »

The TTS allows the cold start valve to turn on a maximum of 8 seconds I believe it is, while cranking, and only while cranking. It's supposed to make starting in cold weather easier. I've experimented and found no difference I could tell down into the 30's, F, but in very cold temps it might make a difference. The FI system has a significant enrichment at starting anyway, aside from the CSV as well as takes into account the coolant and air temps.

There are electronic replacement TTS's, Bosch even IIRC, that don't behave like the originals and run much longer. They can cause problems due to flooding.

So, depending on the temps it might be harder to start. Might.
Mike W.



1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
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