overported tb or bad IAC??
#1
overported tb or bad IAC??
i thought it was just your run of the mill overported tb but after i backed out the idle adjustment screw a few turns the rpms dropped back to normal for a little while (500 idling in gear vs 700). its not much but its enough to throw codes for high idle and lean on both banks.
here's the unusual part, after it was normal for a whlie it crept back up to around 700 and the screw didnt move. now sometimes when i pull up to a light it will drop to 500 and then slowly creep up to 700.
if it was just an overport would it drop all the way down to 500 and then slowly creep up or would it just drop right to 700???
this is the second ported tb to do the exact same thing btw.
here's the unusual part, after it was normal for a whlie it crept back up to around 700 and the screw didnt move. now sometimes when i pull up to a light it will drop to 500 and then slowly creep up to 700.
if it was just an overport would it drop all the way down to 500 and then slowly creep up or would it just drop right to 700???
this is the second ported tb to do the exact same thing btw.
#4
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PCV hose can crack or scuff open. Vac lines
may come loose at the back. Intake bolts may
want snugged. Injector O-rings can get mis-
seated if you played with those.
If you are going to use old-school leak detect
methods (spray propane or carb cleaner) you
should unhook the IAC once motor is warmed
up, so IAC can't fight the drop/rise in RPM you
are listening for.
may come loose at the back. Intake bolts may
want snugged. Injector O-rings can get mis-
seated if you played with those.
If you are going to use old-school leak detect
methods (spray propane or carb cleaner) you
should unhook the IAC once motor is warmed
up, so IAC can't fight the drop/rise in RPM you
are listening for.