meggy 1.4 16v high idle

[karlos100]

Anyone help? as above on a 53 plate. when first started idles at 1000 then slowly creeps up to 2k and sits there singin away. Did have fault with downstream lambda but checked heater feed-battery voltage and it was switching between .2 and .7v. Its the later model no idle control valve so replaced the throttle body. its exactly the same. have sprayed around inlet to check for leaks-none apparent. i found the wires to clutch pedal switch broken off so repaired and refitted=still same. when idling the throttle potentiometer is at 15% im not sure if thats a high reading. anyone know? also when idling the diag machine says idle control inactive.
id have thought if it was drawing air the idle would be irratic rather than constant high.

any ideas chaps?

 

[lemonnobby]

any leaks around the brake servo? i think 15% is about right iirc possible wiring fault

 

[karlos100]

i blanked off the outlet to servo at the manifold end to rule it out. exactamont the same!!

 

[lemonnobby]

just a quick thing have you checked the plugs and the coils as these can spike a few things?

 

[karlos100]

well it dont pick up any misfire and no faults stored at all. ive had the coils off to remove inlet manifold and when refitted used some silicone grease. they all looked ok no signs of arking or cracks. it actually drives well but sometimes has a flat spot when pulling away but only does that once every blue moon

 

[mini-valver]

Map sensor cracked?