[urq] Re: Testing ISVs

[isham-research.freeserve.co.uk at pop.pol.net.uk]

>> My ISV(for the 3B) is open slightly when not connected,
>> I'm guessing for failsafe allow-the-engine-to-idle mode.

> Yup. For the 7A (NA 20V), the early Hitachi plunger-style
> ISVs are closed at rest, but the later Bosch rotary units
> remain slightly open. The BJ test applied across the board
> would have you tossing perfectly good ISVs.

The early units are conical and use a bimetal strip.  They too
are slightly open at rest.  The plunger type used on the turbo 10Vs
(and the 7A, etc.) is made by VDO and is closed at rest.  The rotary
unit is made by both Bosch and Hitachi, and is again slightly open at
rest.

-- 
 Phil