Low idle only when warm

Was running sweet. Not now though. Starts fine hot or cold. It's when I'm nearly up to temp then idle speed is barely above 500rpm.
Originally thought it was misfire but all cylinders have good strong blue spark?
Cheers John 

Try increasing the idle speed, the idle screw can work it self lose as the rubber o-ring gets old and flat.

Its at the back of the throttle body.


Old seal/ o ring


New seal/o ring

 

Mark the idle screw hasn't moved. A few years ago idle screw went 'missing' while on the QE bridge at dartford. Had to fill the hole with some old recipes out my wallet just to get home. When I got hold of another correct screw I wrapped it in ptfe tape and it hasn't budged since. Also if I increase the idle speed, my cold idle will increase to which atm is fine. I want to check the control pressure of the Wur but can't justify buying a gauge right now. I suppose another way is borrow a Wur off someone, swap it over, see if that solves it?

Have you checked the gauze filter in the WUR? These can get partially blocked over time

Soak in carb cleaner and blow out with an air line

Ok I hear that, so does this involve taking the Wur apart fully or just the banjos off? 

Just undo the banjo, can't remember if the large one or the smaller

Just checked it is the larger one!

Nice one, so blow airline through the gauze or through the braided lines or both? Have n got airline but could pop to the local mechanics and ask a small favour...

If you undo the banjo at the WUR end you can see if it's blocked first carb cleaner alone should do it

Ok little update. I've checked voltage at the WUR plug =10.5 v, checked resistance or WUR =20 ohms. It was hard to see if the gauze was caked, sprayed carb cleaner in there just to be sure. I noticed what appeared to be injector 1, leaking a small amount of fuel out onto the inlet and exhaust. removed and replaced the injector thinking I'd found the problem yay. SO went for a drive… problem still remains. seems hesitant on acceleration, really embarrasing at the lights, exhaust pulsing, revs about 400 rpm, battery light flashing. can't understand it. tried spraying carb cleaner around inlet and injector while running can't hear a change in engine note. is it possible the cam belt might have skipped a tooth?
cheers

Hey John, how's tricks? (other than the car woes!) lol

Glad to see you around and you've still got the mk1.

It may be a back to basics job and check timing etc is right, mixture and idle too.

Alright Andy all good here matey, How's your mars red project going?
Ironically, only come on here if have a problem or need some shoppingmust be a good year or two since I posted on here. car was purring like a cat up until the other day

 

Good stuff John.

My project has stood still again since last spring

Lack of time and now need to get it to my unit where all my gear now is before I can work on it again.

next step check over the basic kjet stuff as per my 16v guide:
http://www.vwgolfmk2.co.uk/forum/viewtopic.php?f=37&t=25972

for timing marks refer to my digifant thread but obv ignore all the setup stuff:
http://www.vwgolfmk2.co.uk/forum/viewtopic.php?f=37&t=14915

for ignition timing on the 1.6 i cant remember the procedure but the haynes should cover that