Jim says:
As such, the richer the engine runs, and the poorer your
combustion is, then the hotter your catylitic converter will run. I have
no idea why Aran Guy hd such problems with his Spitfire (mine has hd no such
troubles [knock on dashboard *! *!]) but it suggests there was some problem
from day one (though I would've figured he would have fixed it).
And I say:
Jim's right; I finally figured out what happened, with the help of a smog
tech. I didn't say what it was, so as not to detract from the discussion.
The EGR valve was intermittantly hanging open and leaning out the
mixture at speed. This caused a mild high speed misfire due to LEAN
mixture, and the catalyst got the gas it needed to cause all that trouble.
The point is ANY component of the smog system can in one way or another
adversely affect the operation of the converter, and with said converter
mounted in such a lousy place there isn't much room for error.
By the way, the replacement EGR valve was $134, because of exhaust erosion
of seat, it wasn't possible to clean it like the manuals say.
Aran Guy guy@bevsun.bev.lbl.gov
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