idle valve question.............

[illumin]

Got a "new" idle valve (ISV) from a GTI at the scrappy, put it on and things have improved so it must be better than the old one. Thing is, it's still not 100% so I guess I need another fully working one.......

Question is are the Mk2 idle valves the same as those fitted to other cars (Mk3s/other dubs), or are there differences? Reason I ask is that they all pretty much look the same. Also, out of the valves listed brand new by GSF, the Mk2 ones seem to be the most expensive (£125!). There are a few on ebay, but only one 8v one - if I found a Mk3/Passat/etc. one at the right price would it work on my 8v?

Anybody got any ideas? 

[Mr Blue]

how is your engine running exactly?

did your engine idle without the isv?

[takethefifth]

And i am assuming you have tried cleaning the isv?

[illumin]

Didnt run the engine without an ISV on - cleaned up the "new" one before I put it on.........

Running-wise at the moment, 70% of the time it runs ok. The rest of the time, when I put the clutch in the revs plummet, car tries to stall and oil light flickers on. This happens most when the car has warmed up - from cold it is quite well-behaved. With the last ISV it did that most of the time, so things have improved slightly. My guess is that this ISV is not 100% but less faulty than the last one................

Other things that I have changed to try and solve running problems are as follows: plugs, leads, filters, worn vacuum pipes, rubber bung on rocker cover, blue coolant sensor, timing has been done as well..............have I missed anything?

[Mr Blue]

air leaks. look for split hoses

the main ones are the rubber bung on the rocker cover and the speedo cable that rubs on the rubber inlet hose. Ive seen plenty of split hose

[rubjonny]

I'm using an ISV from a MK3 2E engine on my '90 GTI works perfectly
They are identical to the 1990 MK2 ones, but possibly not the same as earlier ones.

[illumin]

air leaks. look for split hoses

the main ones are the rubber bung on the rocker cover and the speedo cable that rubs on the rubber inlet hose. Ive seen plenty of split hose

The "big rubber hose type thing" that goes from the throttle body to the air filter does have an area where the speedo cable has eaten away at it, but it doesn't look split - maybe I should invest in a power rohr..........

My reasoning for it being the ISV is simply that things have improved with the more recent ISV but as it was not brand new, I presumed it must faulty, although less faulty than the last one..........Can't bring myself to buy a new one - too tight! lol 

I'm using an ISV from a MK3 2E engine on my '90 GTI works perfectly
They are identical to the 1990 MK2 ones, but possibly not the same as earlier ones.

That was what I thought - looking at the ones on ebay at the mo they all look the same.............

[j_s]

It seems you have identical problems to mine, all hoses replaced on mine, tried several isvs, new rocker bung.
In the end we've now found out it's to do with the throttle lever. We've adjusted it and redone the co and idle and it has improved the idle hunting but it's still not right, if the idle hunting starts I can stop it by pressing the throttle a tiny bit and all is ok.

I'm replacing the throttle lever bits including the springs etc to see if that improves it as my accelerator is quite easy to push down on and it seems it should be a little harder to press so the springs might have stretched too much (all guess work here)

[rowlers]

I've said this before - I'm sure but I've had the same issue with my 1990 valver. I fitted a new ISV control module (beind the centre console - controls the ISV - or something!?) THIS HAS CURED MY PROBLEM!!

It only cost £6 off ebay!!

give it a go 

[rubjonny]

There isn't an ISV control module on an 8v, which I assume illumin has got