Service manual

G424F(FE) Service Manual Chapter 6. LPG FUEL DELIVERY SYSTEM 200
AVV (Air Valve Vacuum) Testing
Purpose of Test
Check for excessive or inadequate pressure drop
across CA100 mixer.
AVV Test Hardware
1. Union Tee fitting, 1/4” (6.35mm) NPT
with three 1/4” (6.35mm) NPT x 1/4” (6.35mm)
hose barbs
2. Vacuum hose
3. 0-20” H2O differential pressure Magnehelic gauge
AVV Test
1. Install Union Tee fitting in the hose between the
FTVs and the AVV fitting. Connect this fitting to
the low pressure port of the Magnehelic gauge
(Figure 37).
2. Leave high pressure port of the Magnehelic
gauge exposed to ambient pressure (Figure 37).
3. With the engine fully warmed up and running at
idle (750 rpm) place the transmission in Neutral.
The AVV should be between 5” and 8” H2O of
pressure vacuum.
4. If the measured pressure drop is excessively high,
check for sticking or binding of the diaphragm air
valve assembly inside the mixer. Replace mixer if
necessary.
5. If the measured pressure drop is low, check for
vacuum leaks in the manifold, throttle, mixer,
TMAP sensor and attached hoses.
Figure 37. Magnehelic Gauge Connection
Ignition Timing Adjustment
With the MI-07 system, ignition-timing advance is
controlled by the SECM.
Connection of the MI-07 Service Tool
To use the Service Tool, a USB (Universal Serial
Bus) to CAN (Controller Area Network) communica-
tion adapter by KVaser will be required along with a
Crypt Token (Figure 38). The Crypt Token acts as a
security key allowing the laptop to retrieve the
necessary data from the SECM.
1. Install the Crypt Token in an available USB port in
the computer (Figure 39).
2. With the ignition key in the OFF position, connect
the KVaser communication cable from a second
USB port on the computer to the CAN
communications cable on the engine. (*If your
laptop computer does not have a second USB
port an appropriate USB hub will need to be used).
3. Connect a timing light to the engine.
4. Turn the ignition key to the ON position (Do Not
Start the Engine).
5. Launch the MotoView program on your computer
and open the Service Tool display (Figure 40).
Figure 38. KVaser Communication Adapter
Figure 39. Crypt Token Installed on Laptop