Hi,
I intended to give an extensive reply to your previous thread requesting 'How To's' on inlet manifold removal and other requests , sorry just no time at the moment, but you are past that stage now with the manifold out.
Normally flap problems are due to carbon buildup but you are not the first person to report this is apparently not their case. Over the years I can remember four reports and it boiled down to the flaps fouling on the block ports. If you look at the manifold now it is out you will see the flaps protrude a little from the lower inlet about 5 millimetres at rest, increasing to a little more as they traverse their full range of movement therefore part of flap motion the end of the flaps must be (theorising) within the block inlet port. For some reason they foul, carbon buildup? 'wobble' due to wear? (I'm guessing).
I remember one member resolved the issue by 'bending the flaps a bit more' (memory vague). Another case related first hand on my doorstep by an obviously experienced member who had a spare engine wiring loom and wired up a dry run of the flaps in situ and managed to pinpoint this mechanical fouling with the block port - he resolved it by removing 1 mm of flap with a Dremmel! The block port is divided into two by a horizontal bar (to create air turbulence apparently and another member in the last few weeks reported on here just one flap was catching on this bar - outcome not reported. If the flaps bench test fine this is something to think about.
In answer to your question I do not think the ECU is that sensitive to flap movement, in fact I have the impression it only tests the integrity of the flaps for full range of motion at startup, three such failures within some defined time period and you get an EML
I would refit just the lower inlet manifold somehow and use the rubber tube technique test/observe the flap motion - (pull off rubber tuber on the vacuum actuator and replace with rubber tube and suck, flaps should move normally, vacuum arm should move about 15 mm - tippex!). Worth reading for diagnostics info on flap movement...
hi guys, im new to this site and also a relitivley new a2 owner (12months), i love my little car however i have had a few niggles with it and having paid out at main dealers thought i would seek alternative advice, my latest prob is the engine management light being on, its saying fault p1031...
www.a2oc.net
Andy