Checks And Adjustments - Manitowoc Grove 5540F Service Manual

5540F/YB5515 SERVICE MANUAL
CONDITION: Engine runs too rich on LPG
Verify each item below:
Verify that there are no
leaks into the vacuum port
on the LPG mixer.
Check for clogged air filter.
Check for exhaust leaks
before the O2 sensor.
Verify that the O2 sensor is
working properly.
Verify idle air screw is
adjusted at idle. Fuel trim
valve will have a 50% duty
cycle.
Check for faulty LPG
vaporizer.
CONDITION: Engine will not start on LPG
Verify each item below:
Check fuel shut-off valve.
Cycle ignition switch ON/
OFF, fuel shut-off valve
should click off after 2
seconds.
Clogged LPG filter.
Check for stuck open
vacuum valve.
Check for clogged small air
filter on top of the
vaporizer.
Check for carburetor
malfunction.

Checks and Adjustments

Spark Plug Gap
Check, clean and adjust the spark plugs every 3 months, or
after every 500 hours of operation, whichever occurs first, or
more often if required.
GROVE
Remedy for each item:
Replace or repair the hose.
Repair or replace.
Repair air leaks in the
exhaust system.
See Error Code 13.
Turn the adjustment screw
counterclockwise to lean
out the air/fuel mixture.
Replace if LPG vapor
pressure is not greater that
Atmospheric pressure -
" W.C.
Remedy for each item:
Check for obstructions in
fuel line.
Check wiring and fuse/
relay.
Close liquid fuel tank valve.
Repair or replace LPG
filter. Open liquid fuel tank
valve and check for leaks.
Clean valve. Check wiring.
Clean or replace air filter
and orifice jet.
Check diaphragm for hoe
and damage. Repair or
replace.
Published 10-21-2010, Control# 198-04
ENGINE AND ENGINE SYSTEMS
Thoroughly, clean the spark plugs, including the threads.
Check the electrode gap with a feeler gauge. There will be a
small amount of friction as you move the feeler gauge
between the electrodes, if adjusted correctly. Bend only the
side of the electrode to set the gap.
Past Production Units
Current Production Units
Engine Timing
The engine timing should be checked and set as follows:
1. Connect the timing light to the No. 1 spark plug wire
(front cylinder).
2. Start the engine and let it run at idle.
3. Check the timing on the crankshaft pulley, in relation to
the pointer on the timing cover.
4. Timing should be:
Past Production Units.......... 11° BTDC ± 1°
Current Production Units.......10° BTDC ± 1°
5. If timing needs to be adjusted. Loosen the distributor
hold down clamp screw and turn the distributor
clockwise or counterclockwise to adjust the timing.
6. After adjusting the timing, tighten the distributor clamp
screw, turn the engine off and remove the timing light.
0.035 in (0,90 mm)
0.030 in (0,0762 mm)
6
6-25