Test 33 - Test Recoil Function; Test 34 - Test Engine Function; Test 35 - Check For Fuel Delivery; Test 40 - Transfer Switch Test Operation - Generac Power Systems GP Series Diagnostic Repair Manual

Section 4 Engine Diagnostic Tests
Remove oil pressure gauge and install oil pressure
3.
switch. Do NOT connect Wire 86 or Wire 0 to
switch terminals.
a. Set a DMM to measure resistance.
b. Connect meter test leads across switch
terminals. With engine shut down, the meter
should read CONTINUITY.
c. Crank and start engine. The meter should read
INFINITY.
d. Connect one test lead to Wire 0 (disconnected
from LOP). Connect the other test lead to a clean
frame ground.
measured. If CONTINUITY is NOT measured
repair or replace Wire 0 between the LOP and
the ground terminal connection on engine mount.
If LOP switch tests good in Step 3 and oil pressure
4.
is good in Step 2 but unit still shuts down with a
LOP fault, check all wiring connections between
START-STOP-RUN switch and LOP pressure
module and LOP sender for a short to ground. Any
ground on this wire will cause Wire 18 to receive a
ground, also inhibiting spark from occurring. If a
short to ground is found, replace wire.
Results
If LOP switch, oil pressure, and wiring all test good,
1.
refer to flow chart.
If LOP switch failed, replace switch.
2.
If no pressure was measured, an internal failure of
3.
oil pump may have occurred.
Test 33 – Test Recoil Function
Procedure
Attempt to pull start engine and observe the
1.
following:
a. Does cord pull easily and smoothly?
b. Does cord return with no assistance?
c. Does engine turn over as cord is pulled?
Results
If recoil did not perform correctly, possible problems
could be:
•
Compression release valve on 410 engine could
be broken.
•
Engine could be seized.
•
Recoil could have become detached from flywheel.
•
Recoil mechanism could be broken and not
properly retracting back into engine.
Test 34 – Test Engine Function
Procedure
Remove recoil and front cover assembly.
1.
34
CONTINUITY should
Remove spark plug from unit.
2.
Attempt to turn engine over by hand.
3.
Results
If engine cannot turn over freely with spark plug
1.
removed, the engine has suffered an internal
failure and seized.
Refer to flow chart.
2.
Test 35 – Check For Fuel Delivery
be
(LP Units only)
Procedure
Open fuel valve on the propane cylinder.
1.
Turn engine Power Dial to the #1 PRIME position.
2.
(on the LP3250 skip this step).
Press down on the dial (or Prime Button) for five (5)
3.
seconds to allow fuel to enter the mixer.
Listen for fuel discharging (sounds like air leaking).
4.
a. If no fuel is discharging while holding the
Power Dial down, no fuel is coming from the
Propane
regulator. Refer back to flow chart (BAD).
b. If fuel is discharging while holding the Power
Dial down, fuel is being delivered through the
demand regulator. Refer back to the flow chart
(GOOD).
Test 40 – Transfer Switch Test
Operation
General
Theory
This Manual Transfer switch requires electric power to
operate with the rocker button. The transfer switch will
not transfer to utility mode if the Utility Light is not
illuminated prior to pressing the rocker button. Also, the
transfer switch will not transfer to generator mode if the
Generator Light is not illuminated (this safeguards
against accidental transfer to the generator if generator
power is not present). This test will help identify whether
the switch, the lights or the mechanism is at fault.
Procedure
Before proceeding, verify the position of the switch
1.
by observing the position of manual operation
handle.
a. If the handle is DOWN, the contacts are closed
in the NORMAL (UTILITY) position
b. If the handle is UP, the contacts are closed in
the GENERATOR (STANDBY) position.
With the handle inserted into the movable contact
2.
carrier arm, move handle DOWN.
a. If the handle moved unencumbered from the
Cylinder through the
Diagnostic Repair Manual
demand