13-7. Vacuum Diaphragm Leak Test.
a. Turn the tester vacuum pump on. Adjust the vacuum
pump regulator to vacuum test specifications as shown on
With the vacuum unit attached to the distributor and
mounted in the distributor tester, proceed as follows:
b. If the vacuum advance is above or below specifications,
a. Place your thumb over the end of the vacuum pump
replace the vacuum advance unit. Retest the vacuum advance
and hose and adjust the regulator control knob to give a
reading of 20 inches. The hose must be closed off to be sure
the tester hose does not leak.
13-9. Test Stand Operation.
b. Attach the tester vacuum pump hose to the tube on
Test the distributor on the engine distributor test stand m
the distributor vacuum unit. The vacuum gage reading will
accordance with the operating procedures for the test stand.
hold if no leaks exist.
c. Observe the contact plate while performing the leak
test to test the response of the contact plate. There should
It will be necessary to use the distri-
be instant response to the pull of the diaphragm, moving the
butor pulse amplifier (DPA) whcn
plate without a drag or bind.
using the Sun Electric Corporation
d. If leakage is indicated, replace the vacuum unit
models that are not battery operated.
This will amplify the low level signal
of the transistor ignition system so
13-8. Vacuum Advance Curve.
that it can energize the test stand
Connect the tester vacuum pump hose to the disstributor
vacuum advance unit and perform operations a through c in
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