1989/90 , new free(?) ISC gasket. printed

[fixkick]

the ISC solenoid moves 200 times a second, most this old are worn out ,  30 years, is way way longer than the designer intended this part to last.
it is simply worn out. and now loose and noisy

yes those Nano scopes some blow up at over 5vdc input, watch out for that.
keep it away from the spark coil primary, the back EMF there is over 100v. boom. smoke lets out.


40v -peak to peak here,  use 10x1 probe and win.

https://www.seeedstudio.com/DSO-Nano-v3.html



that front end noise, moving or not or both?  (front lower ball joints, or CVJ Jack shafts, or even struts,  sure the locks can make noise, if stuck 1/2 way, they make ratchet sound, like your finger over comb, but loud and metallic)


good luck, and glad your account works.

[HAPPYNEWVITARA]

the ISC solenoid moves 200 times a second, most this old are worn out ,  30 years, is way way longer than the designer intended this part to last.
it is simply worn out. and now loose and noisy

yes those Nano scopes some blow up at over 5vdc input, watch out for that.
keep it away from the spark coil primary, the back EMF there is over 100v. boom. smoke lets out.


40v -peak to peak here,  use 10x1 probe and win.

https://www.seeedstudio.com/DSO-Nano-v3.html



that front end noise, moving or not or both?  (front lower ball joints, or CVJ Jack shafts, or even struts,  sure the locks can make noise, if stuck 1/2 way, they make ratchet sound, like your finger over comb, but loud and metallic)


good luck, and glad your account works.

According to the scopemeter , my valve is opening - closing around 33 times each seconds . It is finetuning regulating the dutycycle and while I move the throttle screw to maintain the 800 rpm setted in the ECU. So I'm surprised this rattle noise if I open manually the throttle as I can't see on the scope meter big signal variation ( may be I don't catch the rattle moment as I can't trigger the duty variation but only voltage transition) . My nano probe has the x10 reading and from my model manual can bear up to 80v. I made a voltage divider (x1000) and could read the plug spark too to measure time and voltage.
I'll first investigate the left front wheel for the noise , ( in movement only) from the lock as I see the external plastic hub has a crack hole than I'll pass to the ball joint moving by hand. May be a locking ring is lost on the 1000 thread driving shaft. Will tell  and post pics.
Have to be honest, suzuki is my second love. My first love is TOYOTA 4RUNNER 1996 that took me back home 2 times from sahara desert..
I love mechanics + electronics and the desert too

[fixkick]

yes,  my points of view on scopes is from the base line of real scopes with 300v and 600v rated inputs. (TEKtronix here)
Cheap scopes can be as low as 5vdc max, and blow out at the drop of a hat. and use a voltage divider fixes that but really a 10x probe is just that.
The problem is coils of wire, and cars are full of them,  solenoids and relays, look, at the AC Clutch and see 400vdc EMF.  kick backs, it does.
so just know that and not blow up any scope, for sure low end.

the frequency on all 91 to 98 sidekicks is 200 Hz. (or 200 cpS using 1960s jargon)
F = 1/T   (time is from 0v to 12v and back to 0v a full cycle not 1/2)  1mS/div and 5 mS total F= 1/t  1 divided by .005 = 200 hz
the frequency does not change ever only the duty cycle. and with the scope we set it 50/50% 2.5 high and 2.5mS low. low is closed no air flows. (from it)

[fixkick]

I have never scoped any 89, they are very rare. those years. for sure ones that actually run, Just saw my 1st Sidekick running here in the south, in the last full year.
2door 95. red. and ratty shape,
but one of the best 4wd offroad and show cars made, IMO. light + best. and low CG.
see this: http://www.fixkick.com/videos/AVI/kickin.mp4

i forgot to say
to makes sure actual hubs (lockers) are not bad must remove them, and drive, this exposed the bearings to road dirt but do so on pavement say around the block safe.
it simply unbolts, (outer inboard bolts)

[HAPPYNEWVITARA]

I have never scoped any 89,  they are very rare.  those years. for sure ones that actually run,   Just saw my 1st Sidekick running here in the south, in the last full year.
2door 95. red. and ratty shape,
but one of the best 4wd offroad and show cars made, IMO.  light + best. and low CG.  
see this: http://www.fixkick.com/videos/AVI/kickin.mp4

i forgot to say
to makes sure actual hubs (lockers) are not bad must remove them, and drive, this exposed the bearings to road dirt but do so on pavement say around the block safe.
it simply unbolts, (outer inboard bolts)

So as the complete cycle on the 89 is 60ms based on my scope pic it seems it is around 16hz at 50% duty. As the freq doesn't change but the duty yes , I suppose there is a resonance for some frequencyes or a broken spring inside but as it is regulating nicely I don't wanto to open it and risck to loose the regulation. Before this was thinking to double the frequency or change the regulating valve with a newer applying a flange port. We'll see. By now the rattle in some condition is exactly as in this video https://www.youtube.com/watch?v=6tWS7DGXtNA

[fixkick]

I have never scoped any 89,  they are very rare.  those years. for sure ones that actually run,   Just saw my 1st Sidekick running here in the south, in the last full year.
2door 95. red. and ratty shape,
but one of the best 4wd offroad and show cars made, IMO.  light + best. and low CG.  
see this: http://www.fixkick.com/videos/AVI/kickin.mp4

i forgot to say
to makes sure actual hubs (lockers) are not bad must remove them, and drive, this exposed the bearings to road dirt but do so on pavement say around the block safe.
it simply unbolts, (outer inboard bolts)

So as the complete cycle on the 89 is 60ms based on my scope pic it seems it is around 16hz at 50% duty. As the freq doesn't change but the duty yes , I suppose there is a resonance for some frequencyes or a broken spring inside but as it is regulating nicely I don't wanto to open it and risck to loose the regulation. Before this was thinking to double the frequency or change the regulating valve with a newer applying a flange port. We'll see. By now the rattle in some condition is exactly as in this video https://www.youtube.com/watch?v=6tWS7DGXtNA

that noise is just wear,  they all do that, this old but keeps working, so is only noise issues.
F= 1 /T    1 / .060  = 16.7 HZ.     (3 times slower than any  91 up , THANKS FOR that DATA! ) maybe this old ISC is  just 3 times slower to react (mass ) 91 is totally newer design.

one can buy a stepper motor, ISC,  even get them off vast cars sold.  (Jeeps have it, a rotating, ISC valve. stepper motor it is)
make small ARM cpu or Arduino CPU,  program it to do PWM from CPU out ISC port , to stepper, drive.
They make stepper motor drive chips cheap, and makes doing this super, easy. software wise.
even a look up table to do PWM to stepper, works.
There are sold ISC stepper valves in a box new, sold, at say , summit racing. (valve stepper motor and valve body all in one) and 2 air pipes to it.

nice video of a worn out ISC<  classic,   16 times a second STROKED, say , 2hrs a day to work and back. is what.?
1billion cycles in 30 years very light usage.   really amazing to me it didnt catch fire. (or just seize)

EOL is EOL.  once again.  find one on ebay  used and pray for only 1/2 that usage.?

or to like others do,  block it 100% and set idle just like a  Carb, HOT( the TV stop screw does that) but when cold and IAC is wide open the engine RPM may be untenable.


that is about all ways to do it , i think. (if you double the PWM frequency I bet it just acts dumb,  due to huge mass of the valve inside)

[HAPPYNEWVITARA]

I have never scoped any 89,  they are very rare.  those years. for sure ones that actually run,   Just saw my 1st Sidekick running here in the south, in the last full year.
2door 95. red. and ratty shape,
but one of the best 4wd offroad and show cars made, IMO.  light + best. and low CG.  
see this: http://www.fixkick.com/videos/AVI/kickin.mp4

i forgot to say
to makes sure actual hubs (lockers) are not bad must remove them, and drive, this exposed the bearings to road dirt but do so on pavement say around the block safe.
it simply unbolts, (outer inboard bolts)

So as the complete cycle on the 89 is 60ms based on my scope pic it seems it is around 16hz at 50% duty. As the freq doesn't change but the duty yes , I suppose there is a resonance for some frequencyes or a broken spring inside but as it is regulating nicely I don't wanto to open it and risck to loose the regulation. Before this was thinking to double the frequency or change the regulating valve with a newer applying a flange port. We'll see. By now the rattle in some condition is exactly as in this video https://www.youtube.com/watch?v=6tWS7DGXtNA

that noise is just wear,  they all do that, this old but keeps working, so is only noise issues.
F= 1 /T    1 / .060  = 16.7 HZ.     (3 times slower than any  91 up , THANKS FOR that DATA! ) maybe this old ISC is  just 3 times slower to react (mass ) 91 is totally newer design.

one can buy a stepper motor, ISC,  even get them off vast cars sold.  (Jeeps have it, a rotating, ISC valve. stepper motor it is)
make small ARM cpu or Arduino CPU,  program it to do PWM from CPU out ISC port , to stepper, drive.
They make stepper motor drive chips cheap, and makes doing this super, easy. software wise.
even a look up table to do PWM to stepper, works.
There are sold ISC stepper valves in a box new, sold, at say , summit racing. (valve stepper motor  and valve body all in one) and 2 air pipes to it.

nice video of a worn out ISC<  classic,   16 times a second STROKED,  say , 2hrs a day to work and back. is what.?
1billion cycles in 30 years very light usage.   really amazing to me it didnt catch fire. (or just seize)

EOL is EOL.  once again.  find one on ebay  used and pray for only 1/2 that usage.?

or to like others do,  block it 100% and set idle just  like a  Carb, HOT( the TV stop screw does that) but when cold and IAC is wide open the engine RPM may be untenable.


that is about all ways to do it , i think. (if you double the PWM frequency I bet it just acts dumb,  due to huge mass of the valve inside)

Another idea could be to use a rc actuator to move arotating valve . If I remember well theyare using a dutycycle signal to control proportional angle. Dont remember the frequency of of the command

[fixkick]

I have never scoped any 89,  they are very rare.  those years. for sure ones that actually run,   Just saw my 1st Sidekick running here in the south, in the last full year.
2door 95. red. and ratty shape,
but one of the best 4wd offroad and show cars made, IMO.  light + best. and low CG.  
see this: http://www.fixkick.com/videos/AVI/kickin.mp4

i forgot to say
to makes sure actual hubs (lockers) are not bad must remove them, and drive, this exposed the bearings to road dirt but do so on pavement say around the block safe.
it simply unbolts, (outer inboard bolts)

So as the complete cycle on the 89 is 60ms based on my scope pic it seems it is around 16hz at 50% duty. As the freq doesn't change but the duty yes , I suppose there is a resonance for some frequencyes or a broken spring inside but as it is regulating nicely I don't wanto to open it and risck to loose the regulation. Before this was thinking to double the frequency or change the regulating valve with a newer applying a flange port. We'll see. By now the rattle in some condition is exactly as in this video https://www.youtube.com/watch?v=6tWS7DGXtNA

that noise is just wear,  they all do that, this old but keeps working, so is only noise issues.
F= 1 /T    1 / .060  = 16.7 HZ.     (3 times slower than any  91 up , THANKS FOR that DATA! ) maybe this old ISC is  just 3 times slower to react (mass ) 91 is totally newer design.

one can buy a stepper motor, ISC,  even get them off vast cars sold.  (Jeeps have it, a rotating, ISC valve. stepper motor it is)
make small ARM cpu or Arduino CPU,  program it to do PWM from CPU out ISC port , to stepper, drive.
They make stepper motor drive chips cheap, and makes doing this super, easy. software wise.
even a look up table to do PWM to stepper, works.
There are sold ISC stepper valves in a box new, sold, at say , summit racing. (valve stepper motor  and valve body all in one) and 2 air pipes to it.

nice video of a worn out ISC<  classic,   16 times a second STROKED,  say , 2hrs a day to work and back. is what.?
1billion cycles in 30 years very light usage.   really amazing to me it didnt catch fire. (or just seize)

EOL is EOL.  once again.  find one on ebay  used and pray for only 1/2 that usage.?

or to like others do,  block it 100% and set idle just  like a  Carb, HOT( the TV stop screw does that) but when cold and IAC is wide open the engine RPM may be untenable.


that is about all ways to do it , i think. (if you double the PWM frequency I bet it just acts dumb,  due to huge mass of the valve inside)

Another idea could be to use a rc actuator to move arotating valve . If I remember well theyare using a dutycycle signal to control proportional angle. Dont remember the frequency of of the command

sure any servo can work,  of any kind,  and a processor to control it based off ECU (PWM duty rates)
motor , steppers
RC is  same, but is real motor and POT,  take Radio control servo apart what do you see?  this,  https://digitalmedia.risd.edu/pbadger/Ph...ices.Servo
what last is things that last under hot engine hood, at 200F.  not all things like that.