VEMS running without ISV

[V6quattro]

Anyone experience with removing the ISV and running ignition based idle control???
Really like to remove mine for some space.

Tanks

[QuattroFever]

I only use ign based idle. It's not perfect, if you get the rad fan cut in as you are lifting the clutch coming out of a junction it can bog down a little but other than that it runs great without isv.

[Billman]

I run it like this for a long time. The isv was on the car but disabled. It run ok but was not so good when AC came into play.

Run it again with the ISV and it is much better with both systems (isv and ignition based)

[QuattroFever]

Need to adjust throttle butterfly too.
Without isv bypassing a little it won't stay running. Turn off all idle controls. Wind it open with the screw a little when the engine is nice and hot to your desired idle rpm then turn on ign based idle and tweak under different loads.

[V6quattro]

Tanks all for the fast replay. I will remove my ISV than .
I don't have aircon so no need to worry about that.

Tanks

[quattro84]

Of course this will work, but be aware that this isn't an idle "controller" anymore but a fixed idle setpoint. So set it up in summer, may ask for a small adjustment in cold winter.
It works, because you tune it for a single occasion, so whenever you auxilleries turn on and take power from the belt it will make the rpm's a bit.
No real problems unless you exceed your Dutch APK idle speed dictated by engine type and build year. (after 1992 that is)

"Verder is het zo dat de CO meting moet geschieden bij een voor het motortype voorgeschreven toerental (om te voorkomen dat de CO waarde wordt beïnvloed door aanpassing van het toerental). De marge is 50 rpm en na uitlezing van de CO mag -indien de CO correct is- het toerental weer teruggebracht worden in de oorspronkelijke toestand (toelichting bij art 5.2.11 lid 8 )"

M.a.w. je kan en mag dus altijd tijdens de keuring het idle toerental aanpassen moest dat noodzakelijk zijn. I'm not sure what the desiged min and max idle speed is for the ABY engine though.

[A80Avant]

big mistake to remove the ISV on VEMS.
ISV is well designed and on the latest versions accurately handled by the ECU making the idle rock steady on all occasions. Im convinced that if it is not working on any car using vems, its because its not tuned properly or the ISV you are using is duff.

ISV is there to handle various occasions when the engine wont be able to control it merely with ignition timing, and if ignition timing is going too low to keep the idle below 1000rpm, then you will have something like 550-600EGT on idle depending on setup,as timing will be reaching 3-5deg to keep the idle low.

So if you are happy with an idle speed of 1000+ then yes, running without the ISV is a solution

[cooperquattro]

Tanks all for the fast replay. I will remove my ISV than .
I don't have aircon so no need to worry about that.

Tanks

i removed mine from day 1 so have no experience with it on and working,i did this for space mainly,i have had no issues with idle....you do have to reset the throttle butterfly and also adjust the tps setting in VEMS to read "0" as this will be affected

[prj]

Your car will also fail to start and idle in colder climates/in winter without the ISV, because it needs a lot more air to do that and with nothing to regulate it, it just is not going to work.

Of course if you live in a place which never sees negative temps, you will probably be fine.

[GazzaG60]

i ran vems till the end from the start vems 1.1.23 with no isv. get it setup right,including the throttle bodiy base setting and its fine. even in winter.

the first few seconds of startup may be a little less nice shall we say but after that no issues. pay attention to ego settings IIRC.

[Mcstiff]

Your foot can make a good ISV

[prj]

Your foot can make a good ISV

Agreed