idling! any ideas?

[Veedubgt18v]

right
when i start my car it idles absolutely fine, when i have driven it a bit tho this changes. when i stop the revs sit at about 1250 sometimes they stay there and sometimes they drop again to 900 ish. i can 'force' it to drop the revs by reving it to over 3000 when the revs drop when i come off the gas they go to 900. if i dont do this they stay at 1250. has anyone got any ideas? i tried the clean isv trick and resetting my idle. i reckon its a vacuum fault but cant find anything! help!

ta ed

ps its a 1992 8v pb engine

[Overseer]

check all vacuum hoses etc for leaks (or that they're on at all!) and make sure your air filter is clear.

[Veedubgt18v]

yeah i done that, my  filter is clean and the only vacuum pipe i can find disconnected is for the warm air flap in the aribox but this has been off about a year and has never caused bother, i blocked the engine end of it. cheers for the speedy reply!    just gonna keep hunting i suppose! better check the o ring on the idle screw thinking about it

[Overseer]

blocked engine end?

a similar thing on mine was keeping the idle high.. it was meant to be connected to something... along with the fact the brake servo hose on mine was dodgy

g'luck!

[Veedubgt18v]

yeah where the pipe goes into the vacuum circuit i blocked it. oh well i will have to keep looking!

[davidhawkins_78]

When was the last time u cleaned the throttlebody out??

With mine there's was so much sh!t is was stopping the butterfly closing properly and thus engaged the idle switch. Check the throttle cable tension too - could be too tight ... again not letting the throttle completely return to rest.

Lastely check the idle switch - make sure there's no borken or fractured wires.

Hope this helps