Differential Pressure Regulator - just the facts

[Brady Moffatt]

Hi Ben/All,

Obviously, the CISE and CISE3 DPR's are physically similar. I can't see how
they can be functionally identical though. The ECU can't tell the
difference, but how is it supposed to compensate when it thinks it's aiming
for 10mA if it should really be aiming for 0mA.

The nominal adjusting point you refer to is essentially the position of the
metal film in the DPR at that amperage (right?). CISE requires 10mA to get
the film to the point where it allows the same amount of fuel to flow past
as the CISE3 would at 0mA.

How can this be the same?

Cheers,
Brady

-----Original Message-----
From: Ben Swann [mailto:benswann at comcast.net]

Brady,

I am only reporting what is printed in a factory  Audi Service Training
manual for CIS-E3/2.3l
engines.  I think the part no. changes more to reflect year rather than
actual major differences in the part.  I found one cis-e DPR with the same
part no. as on the CIS-EIII's I checked.

Here is what the manual says. "The regulator and its operation is the same
as used on CIS-E fuel injection.  The operating range during closed loop or
oxygen sensor regulation has, however, been changed.  The operating range is
now +10mA to -10mA.  The nominal CO adjusting point is now 0mA.  This helps
to insure better engine operation if an electrical failure should occur by
providing a fuel mixture which is in the range of the nominal setting."

I did check resistance for several(6), incl. cis-e, cis-e3and resistance
typically between 18 and 22 ohm.

Just reporting my findings - you may interpret them as you like.

Ben