https://fixkick.com/sensors/vsv.html
when say the EGR vsv
when driving the VSV EGR opens, and modulates (mod valve) THE egr EXH. FLOW.
THen when you cut the throttle, EGR mode ends. and VSV changes state.
as the VSV closes, it must vent air to the vacuum in the lines or the EGR will hang or be slow to close.
to do this vent action, a filter is needed. at C
those 2 knobs are filters. or filter caps, when others do service on the car they break things and ignore it.
when broken real well, it may even break the actual valve, and if that happens it sucks are full time and the ECU ISC servo actions FAIL HARD.
but is it not amazing how many things can break here and still run, EFI does that.
my engine 2007 year. new pump day,water and rear pump oRING. later I walnut shell blasted my TB. for fun.
![[Image: cover.jpg]](https://fixkick.com/t-belt/cover.jpg)
VSV evap opens driving to suck the nasty gas fumes from CANISTOR carbon can.
VSV DP only opens at first start, for 3 to 15 seconds, colder day, longer. a tad longer.
VSV EGR opens not idle , no WOT, but only off idle or on newer sidekicks only moving car over 1mph 1996+
so parked all 3 are closed, running, and all 3 do not suck air, a.k.a a vacuum leak, making MAP go nuts. (ECU +MAP)
to learn this , run engine at hot idle.
and pull this DP hose see RPM go high, or go high fast then ISC corrects the error back to 800hot.
if you pull this DP hose running RPM goes higher. the more hoses pulled the higher it goes. (adds)
here is my IAC test hole photo, for finding 2 classic failure, IAC stuck,closed or open or gasket blow out causing one more vacuum leak here.
all places to have air leaks are here. 8v. TV down. all leaks can make ISC servo fail for sure larger leaks.
the ISC is dead (means servo dead or it) THIS IS MY ISC test. (to see if it is alive at all)
if
1: hot engine , at idle parked. AC off. rear defroster off (huge elect. current this uses if opted new) steering switch not bad.
2: turn on headlights and blower to high(dash) at the same time, RPM must hold at 800rpm ( 89/90 cars take different test, as HL are fast idle on those 2 years)_
if not the IDLE servo is dead,
3: or if AT car shift in to drive, 800 rpm must hold. in DRIVE, going from N to D.
servo means the software(firm) loop in the ECU that controls idle rpm, is dead. (caused by 2 things, air leaks or in limphome mode = non code 12 is LIMP)
finding air leaks (vac leaks) are not easy to find, only by closing off all things that can leak we find the true leak'er,...
ever see the sci-fi movie.? (forget name but will not forget he great act)
astro _nuts in space ship flying in deep space, the hard vacuum of space.
It gets hit with micro meteorite. bam. holed. but location not known, only 14PSI air pressure falling fast in cabin.
air leaks out, faster than (environment controls can cope)
I love this part, one guy there, takes soda pop can , pops the pop top and leaks out cola.
they all watch in wonder, as the cola, flows to the leak and one guy out side , hey I found the leak here? and hot glues it shut. (now hero status)
same deal here, finding leaks takes hard work ! (can)
long ago , it was said, Nature abhors a vacuum (means on earth not the moon ) no space ships then so. means on earth.
Aristotle
same on car engines, it has vacuum inside, and nature wants to correct that, by any ways possible. (ever day of its life on earth)
even to the point of sucking in a gasket, ending or damaging the perfect vacuum inside.
hoses crack or collapse, my 91 kick the 2 map hoses turned to snot. the rubber was turning to runny glue mess, cheap hoses from suz.
ISC stuck open
air leaks to the intake manfold, lost of ways.
seen one car with TB base gasket with the 5 holes on bottom not blocked. home made gasket made wrong and sucked air.illegal air.
leaks < like gold is where you find them. keep open mind, do not ASSUME. or you will fail many times.
I good mid sent is assume it is all wrong, and prove otherwise, on old cars, this works really well.
the 8v runs great with air leaks, sure does. just idle speeds wrong.
when say the EGR vsv
when driving the VSV EGR opens, and modulates (mod valve) THE egr EXH. FLOW.
THen when you cut the throttle, EGR mode ends. and VSV changes state.
as the VSV closes, it must vent air to the vacuum in the lines or the EGR will hang or be slow to close.
to do this vent action, a filter is needed. at C
those 2 knobs are filters. or filter caps, when others do service on the car they break things and ignore it.
when broken real well, it may even break the actual valve, and if that happens it sucks are full time and the ECU ISC servo actions FAIL HARD.
but is it not amazing how many things can break here and still run, EFI does that.
my engine 2007 year. new pump day,water and rear pump oRING. later I walnut shell blasted my TB. for fun.
VSV evap opens driving to suck the nasty gas fumes from CANISTOR carbon can.
VSV DP only opens at first start, for 3 to 15 seconds, colder day, longer. a tad longer.
VSV EGR opens not idle , no WOT, but only off idle or on newer sidekicks only moving car over 1mph 1996+
so parked all 3 are closed, running, and all 3 do not suck air, a.k.a a vacuum leak, making MAP go nuts. (ECU +MAP)
to learn this , run engine at hot idle.
and pull this DP hose see RPM go high, or go high fast then ISC corrects the error back to 800hot.
if you pull this DP hose running RPM goes higher. the more hoses pulled the higher it goes. (adds)
here is my IAC test hole photo, for finding 2 classic failure, IAC stuck,closed or open or gasket blow out causing one more vacuum leak here.
all places to have air leaks are here. 8v. TV down. all leaks can make ISC servo fail for sure larger leaks.
the ISC is dead (means servo dead or it) THIS IS MY ISC test. (to see if it is alive at all)
if
1: hot engine , at idle parked. AC off. rear defroster off (huge elect. current this uses if opted new) steering switch not bad.
2: turn on headlights and blower to high(dash) at the same time, RPM must hold at 800rpm ( 89/90 cars take different test, as HL are fast idle on those 2 years)_
if not the IDLE servo is dead,
3: or if AT car shift in to drive, 800 rpm must hold. in DRIVE, going from N to D.
servo means the software(firm) loop in the ECU that controls idle rpm, is dead. (caused by 2 things, air leaks or in limphome mode = non code 12 is LIMP)
finding air leaks (vac leaks) are not easy to find, only by closing off all things that can leak we find the true leak'er,...
ever see the sci-fi movie.? (forget name but will not forget he great act)
astro _nuts in space ship flying in deep space, the hard vacuum of space.
It gets hit with micro meteorite. bam. holed. but location not known, only 14PSI air pressure falling fast in cabin.
air leaks out, faster than (environment controls can cope)
I love this part, one guy there, takes soda pop can , pops the pop top and leaks out cola.
they all watch in wonder, as the cola, flows to the leak and one guy out side , hey I found the leak here? and hot glues it shut. (now hero status)
same deal here, finding leaks takes hard work ! (can)
long ago , it was said, Nature abhors a vacuum (means on earth not the moon ) no space ships then so. means on earth.
Aristotle
same on car engines, it has vacuum inside, and nature wants to correct that, by any ways possible. (ever day of its life on earth)
even to the point of sucking in a gasket, ending or damaging the perfect vacuum inside.
hoses crack or collapse, my 91 kick the 2 map hoses turned to snot. the rubber was turning to runny glue mess, cheap hoses from suz.
ISC stuck open
air leaks to the intake manfold, lost of ways.
seen one car with TB base gasket with the 5 holes on bottom not blocked. home made gasket made wrong and sucked air.illegal air.
leaks < like gold is where you find them. keep open mind, do not ASSUME. or you will fail many times.
I good mid sent is assume it is all wrong, and prove otherwise, on old cars, this works really well.
the 8v runs great with air leaks, sure does. just idle speeds wrong.
http://www.fixkick.com