Poor idle and I've done everything! VR6

[John Blount 11]

On VCDS mine shows a steady increase in the throttle angle as I push the throttle it's not 'jurky' or missing bits etc or anything and it returns to about 12.5 degrees at rest which I believe as long as it's below 14 degrees that's fine?

 

Does anyone know where I can get a known working throttle body to try before I replace it, don't mind spending the money but I don't want to just waste it either and buying one off e-bay which won't prove anything if that one doesn't work either, and knowing my luck it will have the same fault!

[John Blount 11]

The only thing that can really go kaput with the TB is the position sensor. Assuming it's clean. Again you can use VCDS to see if it shows a smooth increase in degrees open as you put your foot down on the pedal. It won't show 100% when open, that's normal. Try cold and hot, of course with engine not running!! I had a cam position sensor go bad and not show on VCDS. On my third one now since new so they do go bad.

 

Would a cam position sensor cause my issue though?

[seanl82 23]

I had a cam sensor fault on another VR6 which I had, and it showed on VCDS. The symptoms I had were real lack of power so the fact your car drives well and idle is normal when warm, suggests to me that its fine John.

[John Blount 11]

Thanks for the input Sean, I've found a brand new throttle body but it's £400 OUCH.

 

Don't mind buying it but I need to prove its that first, saying that it's only going to appreciate in value so might end up being a good buy!

[seanl82 23]

I wouldn't bother with a whole new one mate. Pretty sure you can buy the dash pots separately and you can get the tps, other than that its a hunk of metal, butterfly valve and a spring! Unless yours is obviously knackered then save yourself a few hundred quid!

[dr_mat 0]

I wouldn't bother with a whole new one mate. Pretty sure you can buy the dash pots separately and you can get the tps, other than that its a hunk of metal, butterfly valve and a spring! Unless yours is obviously knackered then save yourself a few hundred quid!

 

What he said. ^^^^

 

Or get one off ebay for thirty quid. Who cares if it works or not? If the problem gets no better then there was nothing wrong with your old one.

[John Blount 11]

Is the TPS mechanically held in place internally, do you just un-bolt it and it falls off??

 

I never took that off when I cleaned the throttle body as I wasn't sure if I would adjust something that's been Ok for the last twenty years? Should I have taken this off and cleaned it??

[seanl82 23]

Massive thanks to 'harrier', just popped round his and he let me swap out the sub with his good one. Vagcom doesn't lie, it was.instantly better so the new cheap isv is rubbish. I'll return that one and get a new Bosch one. Think they're around the £250 Mark from VW so I'll try to source one elsewhere. May try Ford!

[John Blount 11]

Sean, is SUB meant to mean ISV? Are you saying that you put a new ISV on originally and have just tried Harriers and it was better? I ask cause I brought a new ISV from euro and that made no difference yet the fault code still says its that??

[Hisnibs 10]

:shades:

[GlosterOx 0]

Does anyone know where I can get a known working throttle body to try before I replace it, don't mind spending the money but I don't want to just waste it either and buying one off e-bay which won't prove anything if that one doesn't work either, and knowing my luck it will have the same fault!

 

I'm pretty sure I've got a good working one in the shed, if yes do you want to borrow it? Probably got a 2nd hand ISV as well!

 

Ian.

Edited February 12, 2016 by GlosterOx

[seanl82 23]

Yeah sorry John, bloody predictive text, it's meant to be isv. Is it the Bosch one you got from ECP that didn't make any difference? I'd take Ian up on that offer if I were you. A known good one will absolutely prove it at least.

[seanl82 23]

Sorry, just realised he meant the tb. If there is someone close by that is willing to,let you swap one in that would be a good start at least before forking out again.

[John Blount 11]

I'm pretty sure I've got a good working one in the shed, if yes do you want to borrow it?

 

Ian.

 

That's very kind mate but I've brought a known working one off e-bay for £35.00 so hopefully that will prove it or not, but thanks very much anyway :thumbleft:

[John Blount 11]

Sorry, just realised he meant the tb. If there is someone close by that is willing to,let you swap one in that would be a good start at least before forking out again.

 

Yeah it was a brand new Bosch one. You changed yours over then and that sorted it did it? Perhaps I've got a dodgy new ISV but I have checked it's working on VCDS and I can hear it operating... I suppose it doesn't mean it's working though.

[seanl82 23]

Yeah it was with the engine warm, but instead of idling at around 1050 rpm, as soon as the good one went in it was perfect at 650-700 rpm.

Went straight back up to 1050 again as soon as I put mine back on. I'm gonna PM Thursdave on here now to see what he can do a new genuine one for.

[John Blount 11]

I think I'm going to buy every single part going and replace then one buy one till its sorted!! Lol

 

I will sort it if it's the last thing I ever do..

[seanl82 23]

Haha, fair enough mate! Good luck with finding the issue, fingers crossed its just a duff new ISV like mine.

[seanl82 23]

Obsolete from VW but available from classic parts through VW Heritage at £185. About a 3 week wait too.

[John Blount 11]

They've been on 3 week back order since October as its the first place I looked, I don't think they bother updating it.

[seanl82 23]

They probably just don't keep them in stock John. They get them from Classic Parts in Germany, and they have a delivery every 2-3 weeks. They'll just order one from there when required.

[John Blount 11]

Arr I see what your saying... In my business if we say there's three weeks back order that's what we mean, didn't think of it like that!

[jekel 10]

Not sure where this is at now but if anyone needs a good Bosch ISV I've got 3 all bang on, look like new inside, had all 3 on car in last few months. Keeping one for spare, sticking the 3rd on Ebay, message me if anyone needs it.

[John Blount 11]

Right... I've had it Terra Cleaned this morning and WOW what a difference that's made, so much smoother on tick over and there's no hesitation at all when you plant your foot down what a difference 40 minutes makes!

 

To be fair though I need to wait till tomorrow to see if this has had any impact on the poor idling as I need it to go stone cold. I suspect it won't have helped that at all but it can't have done any harm either so we will see.

 

The two cans that are used are different of which the first one that's used is for cleaning the injectors and while that was being used you could see from the exhaust all the carbon being burnt off as heavy white smoke, not enough that the neighbours are going to moan but enough that you can see it was doing something.

 

The second can is combustion chamber cleaner that gets rid of all the varnishes off the internal components in the engine, mine wasn't to bad by all accounts as there wasn't much to see coming out of the exhaust.

[Dox 23]

Is the car in daily use or just idling on the drive?

 

In previous years when I've laid my VR6 up over winter its idled and smoked badly on start up, with regular use it does neither, uses 1L of oil every 1K miles.