01-19-2021, 09:18 PM
the 3 tests I do on all 8V for idle problems, vacuum hoses all good and things on the end of them not leaking air.
I block the IAC port on a hot engine to prove it does not suck air hot, if that test fails the IAC is TOAST, (wax pellet inside is DEAD or weak)
there are only 2 ways to block IAC, clay in its suck port up top or the 3 screw cover off and pack clay in there. or a TB base gasket that blocks IAC/ISC air port.
obviously the blocking TB BASE , port, only shows ISC or IAC is bad, or not. and not which one is it fails this test.
the other test is is only for ISC
those 2 tests are , 1: find a way to cut the ISC wire, or pull it pin out of the connector (either of the 2 pins to ISC) kills dead the ISC and is now blocked.
ISC having no PWM 200Hz signals from the ECU goes fully hard closed valve on a normal engine this test causes.
a: engine stall or drops 400 RPM or this act show ISC is mostly working.
b; does nothing the ISC may be leaking. , motivating me to do test 3:
3: This test is to make a new ISC gasket that blocks all 3 ISC ports, this defeats the ISC, 100% and rpm most fall hard, to 400 or stall, if not your air leaks are not in the TB or the TV valve is set way too far open,
on this year car the TV is the idle duty cycle calibration point, so we unscrew it to get 800rpm then turn just a tad more that screw for better regulation;'
or do the duty cycle calib now. (correctly)
in all this checking the DASH pot is retracted, not touching screw with same name seen above. yellow arrow.
the testing for too high idle is all about blocking all possible air paths.
I block the IAC port on a hot engine to prove it does not suck air hot, if that test fails the IAC is TOAST, (wax pellet inside is DEAD or weak)
there are only 2 ways to block IAC, clay in its suck port up top or the 3 screw cover off and pack clay in there. or a TB base gasket that blocks IAC/ISC air port.
obviously the blocking TB BASE , port, only shows ISC or IAC is bad, or not. and not which one is it fails this test.
the other test is is only for ISC
those 2 tests are , 1: find a way to cut the ISC wire, or pull it pin out of the connector (either of the 2 pins to ISC) kills dead the ISC and is now blocked.
ISC having no PWM 200Hz signals from the ECU goes fully hard closed valve on a normal engine this test causes.
a: engine stall or drops 400 RPM or this act show ISC is mostly working.
b; does nothing the ISC may be leaking. , motivating me to do test 3:
3: This test is to make a new ISC gasket that blocks all 3 ISC ports, this defeats the ISC, 100% and rpm most fall hard, to 400 or stall, if not your air leaks are not in the TB or the TV valve is set way too far open,
on this year car the TV is the idle duty cycle calibration point, so we unscrew it to get 800rpm then turn just a tad more that screw for better regulation;'
or do the duty cycle calib now. (correctly)
in all this checking the DASH pot is retracted, not touching screw with same name seen above. yellow arrow.
the testing for too high idle is all about blocking all possible air paths.
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