knock sensor bad?!?

[Preston Brown <pbrown@econ.yale.edu>]

Next problem:

OK, remember about a month ago (or more) when I was telling you that my 
86 5KCST wasn't developing "enough" power?  (or at least, it seemed that 
way.)  I noticed that at highish speeds, I couldn't get the RPMs over 
3000 without the check engine light coming on (fault lite).  I know that 
while driving this lite comes on when there is too much knock and timing 
is being retarded the maximum amount, but I didn't think that it should 
be coming on at 70 mph w/91 gas...correct?

OK well no matter HOW we feel about that stuff, I finally ran the codes 
on the engine (two times w/two drives to verify) and I get engine code 
2142.  According to the bentley, this is "knock sensor wiring or knock 
sensor defective".  That's about ALL that they tell me.  Period.  All the 
other sensors/wiring thingies have much more troubleshooting info.  This 
one they seem to have dropped in my lap.

OK! I say. The computer concurs that there is something wrong with the 
knock protection.  But where do I go from here?

BTW -- as an aside, a little question in relation to my motorized antenna 
saga:  why does that clear vacuum hose attach to the bottom of the 
factory motorized antenna?

---
 -Preston Brown
  preston.brown@yale.edu