T-switch on side of block, Early CIS...

[fahrvegnugen at cox.net (David Utley)]

G'Day,
   I discovered this over the weekend, so I thought I would share my discovery to try to aid the next poor bastard that has the same symptoms...

  What I am refering to is that little abortion of a T-switch that sits on the drivers end of the block, connected to a water hose that shoots off from a hose to the heater core...  It is basically a tube, orginally metal, with a old-fashioned two plug connector...  It's function is to tell the computer when the car is warm, so that it will read the information from the 02...

The symptoms:  At all times, I my Oil Light and Alternator Light would flicker.  This was really obvious at night of course, as it would rarely come on fully, and if it did, it was only a flash, not solid...  The car also drove hurky-jerky quite a bit of the time, and this seemed more obvious when it was under light load, or light throttle...  It was not obvious at highway speeds, but was worsening to the point that it would eventually be so.  The last time I dealt with this, I replaced the EFI brain with a known good unit.  It went away for sometime, until the last few months...  One last symtom, the car was a bit harder to start.  I have a new warm-up regulator, so I knew that was not it...

The fix:  Replace the damn thing!  Once I unplugged it, and put a jumper wire in where the sensor used to be, it ran better...  Disconnecting it made it run better yet, more solid than I remember in a long time...  These sensors are still available, and IIRC, the newer ones are plastic.  Even better!  If need be, and it is warm, you should be able to get by without it jumpered.  Jumpering it puts it in enrichment mode (RICH), so you may have to do so if it is cold, but I would not keep it connected for a prolonged period of time...

Hope that helps someone, it appears to apply to most cars from 80-83 or so...

Cheers,
  David


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