Re: WOT switch

[thyrsted@olsy.dk (Kenn Thyrsted Nielsen)]

Okay, if understand you correctly, this would explain the much better cold
weather performance; the only way i am getting fuel enrichment now is when
its triggered by temperature, not the WOT switch. This would also explain
the smoother torque-build up at revs < 3200.
Is the temp-controlled fuel enrichment gradually, or on/off as in the case
with the WOT-switch ?

Kenn Thyrsted
'87 200tqa

[SNIP]
>There are four engine states:
>
>1) Off (for the pedants among us)
>
>2) Idling
>
>3) Cruising (for want of a better word)
>
>4) WOT (wide open throttle - a misnomer)
>
>The first is irrelevant.  The second is indicated by the idle microswitch
>(throttle closed) and causes the idle controller to optimise engine
performance
>primarily to avoid vibration.  There are secondary inputs for low battery
>voltage and vehicle motion, when a higher idle may be selected.  The third
>state differs not between North America and Europe, but between vehicles
fitted
>with emission controls and those that are not.  In emission-controlled
>vehicles, the ECU maintains a servo loop using the oxygen sensor and the
fuel
>frequency valve.  In non-controlled vehicles, it uses a table-based
>calculation.  The fourth state is fundamentally the same for all vehicles,
>since attempts to optimise for low emissions are abandoned at WOT.
>
>Boost is a separate issue.  European vehicles corresponding to the MC-2
(the MB
>and 1B engines, primarily) use ECU control of boost at WOT just as North
>American vehicles do.  Scott Mockry has come up with a wonderful little
test
>lead for showing this in operation.  The WR engine, in both its North
American
>and all European forms, uses only mechanical boost controls.
>
>I don't know the JY engine, but I strongly suspect it's a variant of the 1B
>especially for Switzerland.  In this case only the third state is different
>from a North American MC-2 engine.
>
>> If your switch has 100 ohms resistance you are missing out on the added
>> fuel enrichment.
>
>Yup.  100 ohms is a bust switch.
>
>--
> Phil Payne
> Committee Member, UK Audi [ur-]quattro Owners Club