teknickle difikulty

[Carl Summers <InTech@writeme.com>]

Hi All,
     Working on a 94 Chev Pu here with Blower and TBI, 7427 4l60E....has
been running well for about 4 years...Runs really poor now...I start with
the basics and check timing and fuel pressure....fuel pressure is good but
timing is 22degrees with est plug disconnected(should be 0)....so I attempt
to move it back and it doesn't like it...dies every time....I notice on the
diacom that the IAC counts down to 0 AND the diacom shows 22 degrees advance
with the EST unplugged....hmmmm....unhook the IAC motor and hook up my IAC
tester/driver and close the IAC completely and engine still idles at
800.....anyway bottom line on the iac stuff is I have a vacuum leak between
the blower and the intake manifold...My question is: Have any of you seen a
spot in the code that increases timing back to what is in the table if IAC
will not lower the rpm enough???? Kinda seems backwards....I was thinking I
had a bad ecm at first since I had an IAC code, EST code and some
others....The timing with and without the EST wire plugged in always matches
what the diacom says so seems as if all is well with the ECM....Oh well just
checking with Y'all if you have seen this before....ttyl
-Calr Summers

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