Bizarre EXUP self-test behaviour

[roxburd]

This is from Pat's site that I linked to earlier, it's quite explicit in stating that you should turn the ignition on and then off to allow for the servo to move the valve to the correct location before making any adjustments;

[color=rgb(8, 32, 128)]Underneath the cover is the Exhaust Valve pulley. It is controlled by two cables. The free play in each cable should not exceed 1.5 mm (0.06 in.). That 1.5 mm is free slack, movement without any pressure at all, not as far as you can push it. Mine were very loose. The 'fork' in the pulley should line up over the hole as shown. If it does not then it may be 30 degrees or more advanced. Turn the ignition ON then OFF. The pulley fork should now be aligned over the hole. If the pulley is not lined up over the hole then the cables are very likely improperly adjusted beyond the tension adjustment. You should loosen both cables until you can manually rotate the pulley until it lines up over the hole (see below how to loosen the cables.) You should do the ignition ON then OFF sequence again to make sure the servo motor is properly zeroed. Then proceed with the tension adjustment.
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Pat's guide is fantastic - a great guide, well written with great photos. Whoever Pat is, thanks for the info, really.

So I followed it - I turned the ignition on and the servo would move the pulley from 20 degrees ANTI-clockwise of the start position even further anti-clockwise against the valve's end-stop. The guide doesn't mention this. As I didn't know what the 'self-test' was supposed to do I didn't know if this was correct behaviour or not. The guide isn't clear on this specific aspect - it says "Turn the ignition ON then OFF. The pulley fork should now be aligned over the hole." Where should it start? Which way should it turn? Does it just go directly to the start position? I expected it to do a fuller end-to-end test to really check the valve can move freely throughout the range, not just move directly to the start position. Was this the cables 'improperly adjusted beyond the tension adjustment' (no, it wasn't) or was it a sensor failure or a failure in the controller?

The 'self-test' is actually just a reset to the start position with a fault signal if there's too much resistance. If the valve is already in the start position (as it would be if I stopped the engine with the kill switch then left it out on the rain in the back garden for 20 years) it doesn't even move at all - that's not much of a self-test really, is it? It's a great guide but if someone ends up in my position it's helpful to know the full picture, IMHO. It certainly helped me in my particular position - my cables weren't 'improperly adjusted beyond the tension adjustment' as Pat envisaged (and designed the guide for), they were improperly adjusted wide of the mark by 30 degrees by a mechanic who didn't know what he was doing.

If you already know what it does or you're just adjusting your cables a bit then Pat's guide is obviously all anyone would ever need, right? But if anyone finds turning the ignition ON and OFF just makes things worse and the pulley is moving in the wrong direction then I hope this info might help them realise what's going on. I guess that's why Pat posted his guide too... we're addressing slightly different starting points though.