ISV problem - Now just a stalling in general problem!

[mic_VR 3]

Afternoon all,

 

After a couple of weeks of my car stalling when warm I finally got around to having a look at it last night thinking it was most likely the ISV being all gunked up.

 

And sure enough the ISV was filthy, so taken that off and cleaned up, but also noticed that the damper box fitted behind it has been broken at some point and not repaired very well. Appears to have been glued back together with silicon sealant :mad: and when I pulled it apart there was only a small amount of the foam left. I'm guess that the rest has therefore been sucked through the ISV and into the engine at some point, which I'd say wasn't exactly ideal? :(

 

So i've ordered a new damper but I'm just wondering if anyone has had a similar issue and what else I should take off and clean in case this foam stuff is causing problems elsewhere?

 

Any help appreciated as I need it back up and running to make the cambridge meet on sunday! :lol:

[CazzaVR 0]

Just take the foam out completely, or remove the damper.

 

Had a stalling prob on mine- the foam had been sucked into one of the ISV pipes. Just removed the whole thing. All you need is a bit of hosing the same diameter as the ISV hoses.

[adamukcorrado 0]

sorry for my ignorance, i know i should know but........

 

Where is the ISV, what does it do? and what is the damper for if it can be removed? only asking as i don't recall anything with foam in it on my engine.

[CazzaVR 0]

The ISV is the Idle Stabilisation Valve, which opens and shuts according to airflow etc and stops the car from stalling/maintains a steady idle. It's at the back of the VR6 engine, under the rear plastic HT lead guide. It will have a couple of air hoses and an electrical plug connected to it. The hoses lead to the black plastic damper pot behind.

 

Well worth removing the ISV and giving it a good soak in carb cleaner, then a good spray with WD40 once clean.

[Taggart 0]

The damper is just to reduce noise I fink.

[adamukcorrado 0]

yep i did know what the ISV is, just not had any reason to think about it on the VR6 yet, i remember having trouble with it on my old 16v.

[mic_VR 3]

CazzaVR, mine hadn't sucked the foam out whole, it has just broken up over time and i'm guessing slowly little bits of plastic foam have been entered the enigne itself.

 

I've now removed the whole thing but wondering how much damage, if any, the plastic might have done to other parts?

 

adamukcorrado, the ISV is a common problem on loads of VW engines, and overtime no matter how much you clean them they still wear out. And as xbones, says the damper is only there to stop you from hearing the clicking noise it makes when it's working properly.

[RS VR6 0]

Without the ISV muffler, you will hear a loud hissing sound from the engine. Its super loud from a cold start. I just ended up putting mine back on.

[CazzaVR 0]

Haven't noticed this at all.

[mic_VR 3]

Ok well I fitting my cleaned up ISV and brand new damper last night and all seemed well, but today it has started stalling again!

 

It seems a bit random ie: it doesn't do it everytime I slow down, but it is getting more frequent everytime I go out in it.

 

Any ideas? Thinking I might look at the fuel supply tomorrow, not sure the fuel filter has ever been changed etc, but not sure what effect that would have on the cars idle...

 

bit lost tbh and the list of things I need to fixs seems to be getting longer each week! :(

[RS VR6 0]

Does it happen right away or does the engine have to warm up?

 

Do you have another ISV to test with?

[vdubjb 0]

I had mine stall at a bridge exit on sunday. The car refused to turn over for well over a minute. Neither me, nor the drivers behind me were pleased.. :twisted:

[scarlet_vr6 0]

thread hijack!! mine has just started doing this too but only sometimes and usually when warm. I'll start with cleaning the ISV, but like mic_VR, I'd appreciate any other advice. My old Polo used to do this and it was cured when I had the leads, plugs and fuel filter replaced. Think my C had all of this last September though... I'll have to look through my svc history to check

[RS VR6 0]

I would check the blue coolant temp sensor. When that goes bad...the car will buck and hesitate...and sometimes stall the car out. Its located on the thermostat housing.

[adevr6 0]

also check wiring to the throttle switch.and wiring to MAF.

[mrbeige 0]

You got this sorted yet Mic?

[vwdeviant 0]

You got this sorted yet Mic?

 

Well HE managed to make it to the Cambs meet... unlike some-one I won't mention :razz: :lol:

[mic_VR 3]

Sorry guys, been really busy and forgot to update this thread.

 

My stalling issue appears to have been cured for now, and as mr deviant said I made it to the cambs meet on sunday.

 

Re-cleaned my ISV and had a look at the fueling. Decided to change the fuel filter and put some fuel system cleaner through and it appears to have done the trick. :D

 

Although, interestingly, the fuel filter I removed appears to be the original that came with the car! so decided to cut it open, carefully, and inside it was black with gunk. So not surprised that the fuel probably wasn't getting through correctly. Guess we'll wait to see if it's cured for good........ :wink:

[mic_VR 3]

Well reluctantly I'm gonna have to open this thread back up because the car is at it again :(

 

This time not only is it stalling when slowing down, the revs are constantly hunting even with your foot on the gas slightly! Damn thing is driving me insane! :mad:

 

So once again, anybody got any ideas on what I should check/replace/smash etc. So far i've... Cleaned the ISV and Throttle body and all associated pipework. Replaced and checked the fuel filter/system (although I'm not 100% sure on the condition of the fuel pump) and checked all the water/oil leak factors, it's not using any water and very little oil.

 

The other weird thing is that I'm still getting 30+mpg so when out on the road it can't be running that bad can it?

[jamminvr6storm 0]

Have you tried unplugging the ISV to see if it still stalls? Same with the MAF, could have a fudged MAF?

 

Also.... maybe a shot in the dark but could it be the lambda?

[mic_VR 3]

Ok today I got a new blue temp sender and some contact cleaner. Going to have a go at replacing the sender, cleaning up the MAF and the lambda.

 

Other than that... I'm stuffed.... Any one in Cambridge got VAG-com and want to come round mine to see what error codes it's throwing out? :?

[drunkenmunkey 0]

I feel your pain, I has exactly the same problem for ages only to find that the PCV breather pipe had a split, I glued it with suger glue & it's cured the problem :? It only ever happened when hot and was completely random.

 

Hope it helps

[mic_VR 3]

I feel your pain, I has exactly the same problem for ages only to find

that the PCV breather pipe had a split, I glued it with suger glue

& it's cured the problem :? It only ever happened when hot and was

completely random.

 

Hope it helps

 

Interesting. Which one is the PCV breather? Is it the one that goes from the rocker cover to the air intake pipe?

 

UPDATE: Have now changed the blue temp sender (no difference) and cleaned up the MAF, which I've not yet tried out on a run but it appears to be working as when I unplug it whilst the engine is running it just dies straight away.

 

A few more things I've noticed now, it only seems to do it when it's warm but it also only appears to happen when the car is actually moving. After I changed the sender today I let it run up to temp until the fan kicked in and all seemed fine, no hunting no stalling and a constant 650-680rpm. So took it out for a run and almost instantly it started playing up, nursed it back home with a bit of swearing and once it's all parked up it idles fine. Rev'ed it up and let off the throttle really quickly and I'm getting a little pop from the exhaust, but nothing major, and it didn't stall/hunt once. Very odd and running out of options..... :(

[VRTrickster 0]

I feel for you aswell, sounds pretty similar to my problem. Which I still havnt got to the bottom of Im afraid !

[mic_VR 3]

Ok, following my day of cleaning the MAF and all the connectors/plugs etc yesterday I took it out for a late night run last night to make sure I got some open roads and low and behold it "appears" to be cured! :D

 

So it seems it was MAF related and the contact cleaner (£2.70 for maplins) has cleaned it up a treat but I'm trying to figure out what caused it in the first place as the MAF is supposed to be heated to 200C for a second as soon as you turn off the engine, this is meant to burn off all the crap etc

 

And the only suggestion is the fact that I'm running a jetex panel filter which is coated with oil, rather than a normal paper one. I'm also thinking that 200C might not be enough to get oil off and thats why it's got worse over time as small oil particles have been sucked off the filter by the awesome power of the V6? :lol:

 

Today i'm off to buy a normal filter, re-clean the MAF and see what difference that makes. Out of interest how many of you are running induction kits/aftermarket filters and suffering from stalling problems??