04-03-2018, 03:52 AM
the 89/90
has 1 not to fun issue.
THE TPS calibration is lost when you adjust IDLE duty cycle. (TV stop screw)
in 1991 suzuki added air bleed screw to the top air horn , curing that pain, forever. (latter cars, do auto calibration (1999+)
air leaks can be found many ways, (vacuum leaks)
1: examining hoses for cracks or fell off. (physical checks of all kinds) EGR gaskets missing or cracked, in fact all plenum things can leak.
The pinch test on most hoses (not all) will solve this, do not pinch map hose. (the brake hose vacuum must be removed and plugged, its huge and can not be pinched. do not drive like this.
2: leakdown testing all actuators on ends of all hoses,
3: the propane test.
4: the water test, spray a device you think leaks and the water blocks it, ive not had any luck with this ever. but water is safe and books love safe.
5: The smoke machine, one guy even used a cigar, to find the leak. ( course next day died of cancer, (dark humor watch out)
6: Dash pot must retract or engine will race for ever.
7: leaks inside the TV< the IAC is prime failure, here. as are other gaskets. Throttle valve and Idle Air controller (100% thermal) it must be closed at 150f and above.
The IAC can be tested, by blocking its ports hot. The IAC water hose must go to 180F if blocked it will not and engine races.
8: PCV hose cracked, omg common. (see it going from top of valve cover to intake manifold.
9: Idle switch not closed, the engine has no idle controls so anything possible, in fact more CARB like, in this failure mode.
10: the ISC can fail it self, it and its funky gaskets.
http://www.fixkick.com/sensors/sensor-ic...-ISC1a.jpg
11 the ECU idle up logic pins failing, there is one pin on ECU and 3 diodes that cause 3 inputs to race engine, (AC on, BLower on, and head lamps on) this pin must be at 0v.
as seen here
http://www.fixkick.com/sensors/tests/IAC...ml#89facts
now a more simple list
1: vacuum leaks of any kind. (can be hard work to find)
2: the ECU is doing this. (inputs to ECU WRONG) idle up, or in limphome mode.
3: the IAC is stuck open for any reason, even water flow to it weak or dead.
has 1 not to fun issue.
THE TPS calibration is lost when you adjust IDLE duty cycle. (TV stop screw)
in 1991 suzuki added air bleed screw to the top air horn , curing that pain, forever. (latter cars, do auto calibration (1999+)
air leaks can be found many ways, (vacuum leaks)
1: examining hoses for cracks or fell off. (physical checks of all kinds) EGR gaskets missing or cracked, in fact all plenum things can leak.
The pinch test on most hoses (not all) will solve this, do not pinch map hose. (the brake hose vacuum must be removed and plugged, its huge and can not be pinched. do not drive like this.
2: leakdown testing all actuators on ends of all hoses,
3: the propane test.
4: the water test, spray a device you think leaks and the water blocks it, ive not had any luck with this ever. but water is safe and books love safe.
5: The smoke machine, one guy even used a cigar, to find the leak. ( course next day died of cancer, (dark humor watch out)
6: Dash pot must retract or engine will race for ever.
7: leaks inside the TV< the IAC is prime failure, here. as are other gaskets. Throttle valve and Idle Air controller (100% thermal) it must be closed at 150f and above.
The IAC can be tested, by blocking its ports hot. The IAC water hose must go to 180F if blocked it will not and engine races.
8: PCV hose cracked, omg common. (see it going from top of valve cover to intake manifold.
9: Idle switch not closed, the engine has no idle controls so anything possible, in fact more CARB like, in this failure mode.
10: the ISC can fail it self, it and its funky gaskets.
http://www.fixkick.com/sensors/sensor-ic...-ISC1a.jpg
11 the ECU idle up logic pins failing, there is one pin on ECU and 3 diodes that cause 3 inputs to race engine, (AC on, BLower on, and head lamps on) this pin must be at 0v.
as seen here
http://www.fixkick.com/sensors/tests/IAC...ml#89facts
now a more simple list
1: vacuum leaks of any kind. (can be hard work to find)
2: the ECU is doing this. (inputs to ECU WRONG) idle up, or in limphome mode.
3: the IAC is stuck open for any reason, even water flow to it weak or dead.
http://www.fixkick.com