Re : '89 200TQ Decceleration cut-off valve, OXS sensor

[Dave Lawson <dlawson@digitalglobe.com>]

Igor,
>
On the Decceleration cut-off valve:
1. A voltmeter is hooked up in parallel to the Cut-off Valve connector,
which remains pluged in.
2. The RPMs are risen above 2000 after which the throttle is released,
slamming shut.
3. The meter reads 90mv (~0v as far as this test goes), although should
read 12v.
4. Idle switch checks OK.

based on =A7=A71-4 Bentley concludes: replace Decceleration Valve Control=

Unit.
Before I do that, anyone BTDT?
Given the horrendous appetite of my red Q (15mpg city), this may very
well be the case. Maybe the fuel is not being cut off when I brake with
the engine.
>
Can't comment on the above test, but in my engine swap, 89 200 MC
int my ur-q, I didn't plumb in this decel valve, and everything works fine.
On my cyberdyne a/f meter, when rpms are above 1200 and throttle
is closed, the o2 sensor reports no fuel, ie no bars are lit on the gauge.

>
Also,
On the OXS sensor:
1. My Wavetek multimeter is connected to the OXS test connector, i.e.
"common"(black lead of the meter) to brown and "V/f/%"(red lead of the
meter) to double Blk/Blu.
2. The connector of the Decceleration cut-off valve is unplugged. The
terminal 2 of the harness side of this connector is jumped to chassis
ground.
3. The meter should read 40% duty cycle steady regardless of the engine
speed.
4. In reality the meter reads 60% steady regardless of the engine speed.

Is it possible that I am reading the same duty cycle, only my meter's
aquisition occures on the rising front, whereas the VAG factory test
device uses the falling front or vise versa (60%=3D100%-40%). =
>

Have never done this test, I just use this test connector to set the o2
duty cycle by tweeking the CO adjustment. At present mines about 30%, 
trying to get on the rich side. One tip from PDQSHIP is to not use the
test connector gnd, connect up to the ground junction on the intake
maifold. BTW I use my sunpro 7678 in the duty cycle mode for this 
adjustment.

-
Dave