VR6 Idle when cold?

[GB_SEAN 0]

Ok so I did the timing chain job put the thing back together, I know that when you dip the clutch the revs drop to about 500 and pick back up to 700/800 idle, but when I start it from cold it won't idle at all as it drops to low. If I drive it for 1 mile it will idle.

 

I know I will be advise 'get it on VAG-COM' but am asking for other peoples experience of this.

 

I don't suspect the coolant temp sensor as everything works except for idle until you drive about a mile down the road.

 

Thanks for any help.. :mad:

[Kevin Bacon 5]

I know I will be advise 'get it on VAG-COM'

 

Get it on VAG-COM

[GB_SEAN 0]

Kev,

 

I think you've answered this before on a diffrent thread. The damper on the throttle body can be adjusted so it dampers the revs slower allowing the ISV to cut in time to adjust the revs.

 

As this hs all been off the car it sounds like this has to be the probable cause?

[dr_mat 0]

Doesn't seem likely to me. Idle isn't controlled by the throttle damper. If it doesn't idle when cold the most likely solution is a temp sensor. And considering you had to remove the temp sensors to do the timing chains...

I suppose you may have a vacuum leak somewhere causing problems, but I would suspect the temp sensors first.

[GB_SEAN 0]

Ok, So now I need to find someone local with VagCom 2x2 connector, The sticky is not very up to date.

[Kevin Bacon 5]

Try moving the blue temp plug onto the black sender first....

 

There's no reason to suspect the senders are broken because they were taken off but a vacuum leak could be a possibilty given that all of the induction parts of the engine were removed.

 

It's the way you said it won't idle from cold because the revs are too low that suggests a vacuum leak. Even with the ISV unplugged, the engine will still start and run.

 

I would go through all the induction parts and check for leaks etc.

[GB_SEAN 0]

So the black temp sender is the same resistance as the blue? Will give it a go?

[Kevin Bacon 5]

Yeah I think it is, it's for the air-con if fitted.

 

Have you got an multimeter? Can always check the resistances with that.

[GB_SEAN 0]

I have means of getting one! Do you know the resistance by any chance, not to worry of not I have a Bentley manual.

[Kevin Bacon 5]

Sorry no, should say in the Bender....

[GB_SEAN 0]

Now kev I am surprised, I thought you knowledge of the VR was bottomless!

[Kevin Bacon 5]

Now kev I am surprised, I thought you knowledge of the VR was bottomless!

 

LOL, your wallet needs to be bottomless as a VR owner more like!

 

I don't get involved with sensors mate, I just replace them if they go out of spec, LOL!

 

But essentially, if the resistance of the BTS doesn't change as the engine warms up, it be buggered!

[GB_SEAN 0]

Got the meter anyway so will do as many as poss tomorrow.