VR6 cold idle issues(video included)

[borachris 0]

Hi Guys,

 

I bought this VR a few weeks ago, it had been stored for a year because of this issue and the guy didn't think it was reliable enough for him to use as a daily.

 

He had a garage take a look and they replaced the ISV(tried a couple of them i believe) as well as new plugs and leads.

 

I've given it an oil and filter change(£60's worth :shock:), cone filter and changed the blue CTS, also have a fuel filter to fit but not got around to it yet.

 

Whilst changing the CTS I replaced the coolant, after filling it up whilst I was squeezing the rad pipes i've noticed a metallic clanking noise so it needs a new thermostat now too!

 

Here is a video of the issue

 

 

Basically it does this whenever started after being left for a couple of hours, as the video shows after revving it a couple of times it stops hunting and settles to a slightly rough idle, if you let the revs drop too quick it will stall, but only during the first minute or two of running, after that its fine although the idle is still a little rougher than i'd expect.

 

Vagcom shows ISV and Lambda faults, although i'm wondering if the ISV could be a wiring issue due to the fact the garage tried changing it and it had no effect?

 

I've started buying parts to drop in a 24v after all the xmas stuff is done, so don't really want to spend too much money on it but it would be nice to get it running better for the next 3 months or so.

 

When up to temp i've tried unplugging the MAF, the engine note changes but it doesn't stall like a lot of people say it should, should unplugging the MAF really cause the engine to cut out??

 

Thanks for taking the time to read my essay(and hopefully reply )

Edited October 19, 2012 by borachris

[borachris 0]

No one have any input? :(

[floppyman 0]

When you say vagcom shows isv and lambda, does it say isv adaptation and/or lambda limit? The whole designation helps.

Check the plug at the air mass meter, with engine running have a play around with the plugs and see if theres any difference.

Check for air leaks crankcase breather is a good place to start looking.

Its going to be a long diagnostic since this is all but very common to the obd1 vr6 engines.

[borachris 0]

Thanks floppyman

 

I will check vagcom again over the weekend and make a note of the full fault description for lambda and ISV

 

This is what the breather looked like

 

 

I've tidied it up and blocked the hole in the intake elbow properly, also temporarily relocated the crappy little filter to the bottom of the subframe with a longer hose until I sort a catch can, it was spewing out quite a bit of oil vapour and covering everything!

 

I've tried playing about with the MAF plug and it doesn't make any difference unless fully disconnected.

[floppyman 0]

I dont recomend that filter at all. Mainly due to the ecu already counting the extra air mass thats going unmetered. That alone might affect things... But dont think its enough to do what youre experiencing.

Is the isv new?does it look new? What brand?

And a isv adaptation might help aswell... But remember... Make shure its all air tight... No leaks.

[borachris 0]

I wasn't sure about the breather tbh, I didn't think it would miss a bit of hot sticky air lol

 

ISV looks new yes, not sure on brand I will check tomorrow, I'll also have a look for leaks, is a spray bottle of water the best method to find small leaks do you think?

[floppyman 0]

Not really... One way is using a can of brake cleaner or carb cleaner and spray aroud the intake pipes while the engine is idling. If you notice a different engine note or rised rpm the you have a leak around the area youre spraying..... But the old fashion is still a good one (take pipes out and have a look):sly: have a look at the isv damper box aswell since some members have had some problems with the foam inside of it breaking down

[CazzaVR 0]

As above /\/\

 

I'd get rid of that breather set up and get the proper PCV valve on there. If that doesn't sort it, my money's on the intake/ISV pipework. There's either a split somewhere, or the foam from the damper pot is blocking a hose. Take them all off and make sure they're all clear. Not a big job at all :)

[borachris 0]

Ok guys, I appreciate the input and will be having a look at the points you've mentioned

 

I am a little confused though, the things you have mentioned, surely these would cause an issue all the time, not just the first 2-3 minutes of cold idling?

 

I'm not saying you guys are wrong, It just doesn't quite add up to me that's all

 

I should get a chance to check a few things tomorrow :)

 

Edit:

 

Cazza, the PCV valve, is that just a one way valve? It has a 2 pin plug on it, I'm assuming that is just a heater in case of the valve freezing up?

Edited October 20, 2012 by borachris

[CazzaVR 0]

Yep, positive crankcase ventilation. One way valve- that plug is just a blank on UK cars.

 

On one of my old VR6s, it would really struggle to idle from cold, OK once warm although it would still stall at junctions etc sometimes. Turned out to be foam from the damper pot that had been sucked into one of the ISV hoses.

 

It's worse when cold because of the cold map on start up.

[Stonejag 10]

If you have a cone filter fitted then make sure you've got some sort of bracket to hold it in place. The rubber inlet elbow is a little stiffer than the plastic one but the weight of an unsupported cone filter on mine caused the MAF wires to fail through metal fatigue from the constant movement. Keep an eye on it!

 

Stone