Whats an ISV?

[theRuler 0]

is it this?

 

[andy 0]

Yes it is, idle stabilisation valve, one part of the feedback loop that controls the idle speed on your engine. The electrical connections supply a voltage that determines how much air passes through the valve and therefore into your engine, thereby controlling the idle speed.

[fla 9]

Yes, and its one area that causes immense problems in a C.

[theRuler 0]

cheers fellas right then i will fetch the fooker off now and clean it.

 

i might leave it off.

[Kevin Bacon 5]

And indeed other VWs that use it....MK2 Golf 16Vs used to cut out at junctions aswell. 8Vs were better but still did it occasionally.

G60 C's rarely cut out though, if ever, so I wonder if it's air volume related? Both the valver and VR6 flow a lot more air than the 8V/G60 engines and perhaps VW just underspecc'd the VR6 ISV and it's not man enough for the job..... prolly talking pap but it's just a theory that popped into my head :D

 

Mine only cuts out once or twice a fortnight though, so it's not a major problem for me but others suffer daily occurences!

[theRuler 0]

mine cuts out more often than the winner of a paper chain contest.

[dinkus 10]

mine cuts out more often than the winner of a paper chain contest.

 

:lol:

[kerrinmay 0]

Is this problem know to affect the 2.0 16v? Because my cuts out occasionally when I pop it out of gear slowing down at a junction for example. It's when the car should be idling but seems to fail to and the revs drop and it cuts out. Always re-starts straight away though.

[2cc 0]

Hey Kev, why haven't we thought of this one before - bored and flowed ISVs to improve air flow volume :)

[Kevin Bacon 5]

Is this problem know to affect the 2.0 16v? Because my cuts out occasionally when I pop it out of gear slowing down at a junction for example.

 

Yep, MK2 16Vs used to do it too as mentioned earlier. There are just some things VW have never got right and idling is one of them!

 

Still, all the best relationships are tempestuous ones :D

[kerrinmay 0]

Are they expensive (and easy) to replace on a 16v?

[Kevin Bacon 5]

Hey Kev, why haven't we thought of this one before - bored and flowed ISVs to improve air flow volume :)

 

I tell you what, we could put a schrick on it which would give it more ooomph at 650 rpm? :lol:

[Supercharged 2]

G60 C's rarely cut out though, if ever, so I wonder if it's air volume related?

 

Maybe, I know the ISV actually vents off boost above 0.8 BAR....

[theRuler 0]

right i got it off, and filled it full of carb / choke cleaner

it can soak for a bit.

 

couldnt i just leave it off and plug up all the holes?

[Kevin Bacon 5]

You could but it won't drive very nicely though.

 

I ran around with the ISV disconnected on mine for a few days as an experiment and it was sluggish and idled too fast.

[theRuler 0]

i'll sling it back on tomorrow then.

i hope cleaning this makes it all run better.

[theRuler 0]

well i put it all back together, and it runs like shit still

 

misfires up to 2000 revs. gonna have to take it to the dealer and see their vag-com thing can detect whether the lambda has died.

 

will they charge me much just for a diagnostic?

[dinkus 10]

Someone on here should be able to help? ;)

[coolrado 0]

im not sure but i didnt think an isv would cause a misfire :|

is it a misfire or does it just struggle to pick up revs?

any different when its hot?

[Son of a Beesting 0]

Same thing is happening to my G60 C, but mine dont misfire just struggles. When it gets hot its worse. Can stall after a journey, when I depress the clutch. Revs drop, then stalls. Very embarrasing if people are near by :cry:

 

Also when I floor it, it judders like its struggling. Guess the vacuum hose could need replacing as well. If its not one thing its another, lucky it makes me smile so much when she runs right :D

[theRuler 0]

Someone on here should be able to help? ;)

 

thanks bud

[dubweiser 0]

Basically an isv is the devil incarnate!!!!!!!!!! :evil:

[theRuler 0]

i just phoned my local vw garage in stafford

 

lol they "took my number" and will get back to me.

 

yeh right, like they are going to call back.

 

the people at my local have always been arrogant in the past, and they seem to have little or no product knowlege.

 

the parts dept guy is fairly friendly (although he did tell that the r32 has 420 bhp, and that vw never made a corrado that cost more than 16K)

[theRuler 0]

i just called in at vw stafford

 

they want 40 quid + VAT to hook it to the vag-com

 

the guy at the desk said it may be too old to plug it in.

i said " do what mate its only 10 years old!!!"

to which he replied "cars have come a long way in 10 years"

 

smarmy twat

 

at that point they had already lost the business.

 

and a new lamda is about 95 quid. doh

[Kevin Bacon 5]

£95! They were £70 last time I got one....obviously prices have come on a long way in 10 years too...