1.8 SE high/sticking idle - any common faults?

[cняis]

95 mk3 1.8 90HP

Right, the daily dogwagon was recently suffering with erratic idling when hot, plus near stalling at junctions etc. Replaced a split vac hose and voila it's fine.

A month on and it's developed a slight high idle issue (around 1000rpm at times compared to the usual 750/800rpm) and an occasional lumpy idle.

I have quickly checked the vac hoses and they seem fine, but there's a slight noise (possibly air?) around the 'carb' (I say 'carb' because being a 90hp 1.8 it has the old-fashioned single point injection i.e. no throttle body [and no idle air valve?])

What could be at fault?

[spudboy6]

95 mk3 1.8 90HP

Right, the daily dogwagon was recently suffering with erratic idling when hot, plus near stalling at junctions etc. Replaced a split vac hose and voila it's fine.

A month on and it's developed a slight high idle issue (around 1000rpm at times compared to the usual 750/800rpm) and an occasional lumpy idle.

I have quickly checked the vac hoses and they seem fine, but there's a slight noise (possibly air?) around the 'carb' (I say 'carb' because being a 90hp 1.8 it has the old-fashioned single point injection i.e. no throttle body [and no idle air valve?])

What could be at fault?

i know this thread is old but im bringing back to life as it never got a reply and i have toe same issue and i used the search found this and could do with some help .

mine idles at 950 and ive noticed its started drinking fuel . the idle feels lumpy but you dont see the rev counter moving . unlike the above i have no stalling issues just high idle .

i have vag com'ed it and it says hall sender if i remember correctly . will get is back on tommrow to be sure .  but any one have two pence to throw in ?

cheers guys

95 1.8 SE 90bhp ADZ manual

[sam1990]

check the rubber flange between the inlet manifold and single point there common to split

[spudboy6]

check the rubber flange between the inlet manifold and single point there common to split

Had a loom today and from what I could see the front is perished badly so who knows what's hiding round the back .

One on order .....

[spudboy6]

Replace gasket/ rubber block this morning an fitted new vac hoses , still have a 900rmp idle ??

[sam1990]

ok well now the flange and vacuums have been sorted you need to clean up the mess its left behind, so start with cleaning the single point out, you dont necessarily need to take it off bit make sure you get it nice and clean also whip the plugs out and give them a clean up at the same time (not that the plugs will cause high idle but more than likely are dirty now) does it have any cold start issues at all? as the automatic choke on thoes single points are notorious for going wrong, have you or anyone touched the throttle cable tension? make sure the throttle cable is not taught at all there is supposed to be some slack in the cable and at the same time make sure the butterfly fully closes as when dirt builds up around the outside of the butterfly it prevents it from fully closing which obviously in return will cause high idle/reving

[spudboy6]

I cleaned it all out when it was off with injector cleaner , but will try the throttle cable ! I did adjust it to take some of the slack out of it , so may have over adjusted,

P.s no cold start issues

[DS1991]

i had similar issues on my 1.4 se and found the lambda sensor was duff and the airbox was all cracked and leaky

[spudboy6]

Plugged in vag con today , only had a quick look and it said hall senda fault.  Changed gasket on the intake , have noticed the idle is lumpy and does hunt