hunting idle when cold

[missfire]

Originally Posted by Gouldy

yes it does mate, will try to source one i think as im sure it should cut out if you unplug it?

mine speeds up if you unplug it..................

if it works you should be able to hear it 'buzzing' on first ignition...
mine kind of goes.....'on...off....on...off...on...off'

[Gouldy]

ah ,there maybe something there then,

also the fuel pump is very noisey, but it drives fine and makes a noise all the time

[missfire]

Originally Posted by Gouldy

ah ,there maybe something there then,

also the fuel pump is very noisey, but it drives fine and makes a noise all the time

my pump makes a fair bit of noise too....am keeping my fingers crossed..but know it will need a change one day..

at least..if they are making noise....we know they are working..!!

mine makes far more noise when the fuel level if low....turns the fuel tank into a big resonator...!

[Gouldy]

haha, i havent noticed any change in noise with the tank tbh lol,

will try and have a play with the sensors/switches at the weekend i think, see if i can see anything untoward

[quattrokid]

could it be the throttle body switches on the side? 1 for idle and the other wide open throttle?

or the warm up reg valve?

[Alfashark]

I know there's a lot of talk about ISV's going on here but...
My KV had a pig of an idle when I got it, replaced all suspect breather hoses but still had the funky idle

Try this - disconnect the vacuum hose to the brake booster and bung the end up! Solved my problem
Booster diaphragm has a pinhole, so the whole unit will be replaced shortly... Strong legs so braking isn't an issue in the mean time

[Gouldy]

right guys, just had a text from the guy rebuilding the head and he said its still running lumpy when cold

its had new injector collars and o rings, new headgasket, new plugs, rotor and dizzy seem fine

again when its hot it runs fine but when it first starts up it hunts, i have taken off all the vacuum hoses and they all seem fine, when i unplug the ISV nothing changes, likewise with the Cold start injector

any ideas?? or anyone willing to pop around in the next few weeks and have a gander for me?

[Gouldy]

got a bit further on this today , got a circuit tester light on the ISV and the Cold start valve and NONE have live when running or with the ignition on ....

do they run off the same relay?? if so i probably need a new one... checked all fuses and all ok

[Gouldy]

does anyone know if i can just run a new live to the ISV?? so that its on whenever the ignition is on, likewise with the warm up reg???

or do they HAVE to run to the ECU etc

not overly worried about the cold start valve/injector as the weather doesnt get THAT cold down here

[Phil Payne]

Originally Posted by Isimmo

Yes, the cold start injector is up on the inlet manifold, we run both of ours disconnected all year, they're ideal for very cold starting, but with the uk's temperate climate they can, even when working normally, flood the engine when cold.

Bolleaux.

There's something wrong with your systems - probably they've been set over-rich to start because something in the cold start system is bust. The idea that Audi would ship hundreds of thousands of cars with cold start valves fitted that they don't need is ludicrous. They do hot start tests in Death Valley, for heavens' sake.

I hate to think what your fuel consumption is.