Mk2 16v Q's

[Gambit]

1. the idle adjustment screw on the throttle body, mine is missing the end cap, and i also have a little air leak there due to an ill fitting o-ring (cant get one that fits properly)

will the cover cap stop the airleak? at the mo i just have a little bit of grease round the o-ring

2. ISV Q

last night mine decided to go tits up with the rev's bouncing between 2-4k misfires backfiring the heap!!

it wasnt that far from home, so got it home just and give the ISV a good clean out and the points a clean just for good measure - this did seem to do the trick

but is my ISV functioning correctly? if i have the car idlin at 1k and i disconnect the red coil wire there is no change, ive been told the revs should plummet?!?

u can hear it prime when the ignition is switched on

3. Coldstarting - mine is a dog to start first thing in the morning (fine all other times throughout the day)

only things i need to test for this are the cold start valve & the thermotime switch??


sorry if its a bit long winded but im gonna have a try and get it all sorted on saturday before winter really kicks in

Cheers,
Craig

[golfvr6]

1. A new o-ring should do the trick.
2. Idle sounds ok, around 1000 sounds cool as long as it stays like that!
3. Look at cold start valve if cold start is poor.

[Gambit]

is it possible to clean out the coldstart valve? or is it just a case of getting a replacment?

[golfvr6]

I'm not sure, might just be better to replace.

[The VolksWizard]

A little tip.
Check that the earth cable that runs across the top of the gearbox hasn't corroded at either end (battery or bellhousing).


The ISV should vibrate at all times when ignition is on.
Just touch it and you should be able to feel it, sometimes you can even hear it.  If is vibrating and you have already cleaned it out, I'd say the problem lies elsewhere.

If you want to check that it works for sure, just pull the wiring plug out of the end of it, if engine dies, it was working!

Good luck!

[Gambit]

all earths are fine - that was the first thing i looked at

on the ISV, this is the thing though, if i pull the plug out of the ISV when its running, it does absolutely nothing to the idle!

but you can hear it when you first switch the ignition on

i'll have to try the touchy feely trick to see if its vibrating when the engine is running

[richandhazel]

Here's some info that may help:-

http://homepage.ntlworld.com/richandhazel1/gti/profix/fuel/isv.htm#ISV

[tobz.]

Gambit
Are you sure the thing you say you hear when you first switch the ignition on isn't your fuel pump???
The main pump runs for about a second to build fuel pressure prior to starting and it makes a buzzing sound.

Toby

[Gambit]

nah, i done the contortionist act of having the bonnet open while keep my ear under the bonnet while stretchin with my arm to turn the ignition on!!!