RE: Dwell angles

[paul.heneghan@bbc.co.uk (Paul Heneghan)]

From: phil
>paul.heneghan@bbc.co.uk (Paul Heneghan) writes:
>> From: Mike Walder <miwa@premier.co.uk>
>>
>> >I . . .  decided to check out my dwell angle.
>>
>> >Thing is, the Haynes manual suggests an angle of between 43=BA and 
65=BA. =
>> > At
>> >1000rpm, the meter measures about 16, at 2000rpm about 30, and at 3000 
or
>> >more about 45.
>>
>> Presumably we're talking about the dwell angle of the ISV.

>Not at 3000rpm, we're not.  The ISV shuts when the idle switch goes open
>circuit.

Yours does, mine does, but from the sound of it, Mike's doesn't.

Mike, you are getting a reading directly proportional to speed.  Check that 
the meter is set to dwell and that you are measuring across the ISV.  (If 
you measure between ground and the switching terminal of the ISV, then you 
will get inverted values, because from what I can dimly remember, the ISV 
has 12V on one side and the switched voltage on the other).

I would expect to get a large value at 600 rpm, a mid range value at 800 or 
900 rpm (check Haynes for correct idle speed setting), and a low value (or 
even no voltage) at greater than 1500rpm.

Paul

p.s. these are predictions and half remembered facts from 4 years ago when I 
fixed my ISV controller.