Troubleshooting - Graco Express 3900 Operation

Troubleshooting

Troubleshooting
Problem
Engine will not start
Engine operates, but displacement
pump does not operate
14
Cause
Engine switch is OFF.
Engine is out of gasoline.
Engine oil level is low.
Spark plug disconnected or damaged.
Engine is cold.
Fuel shutoff lever is OFF.
Oil is seeping into combustion cham-
ber.
Pump switch is OFF.
Pressure setting too low.
Fluid filter is dirty.
Tip or tip filter is clogged.
Displacement pump piston rod is stuck
due to dried paint.
Connecting rod is worn or damaged.
Drive housing is worn or damaged.
Electrical power is not energizing clutch
field.
Clutch is worn, damaged, or incorrectly
positioned.
Pinion assembly is worn or damaged.
Solution
Turn engine switch ON.
Refill gas tank. Honda Engine Manual.
Try to start engine. Replenish oil, if necessary.
Honda Engine Manual.
Connect spark plug cable or replace spark
plug.
Use choke.
Move lever to ON position.
Remove spark plug. Pull starter 3 to 4 times.
Clean or replace spark plug. Start engine.
Keep sprayer upright to avoid oil seepage.
Turn pump switch ON.
Turn pressure adjusting knob clockwise to
increase pressure.
Clean filter.
Clean tip or tip filter (see gun manual).
Repair pump (see pump manual).
See Parts manual.
See Parts manual.
See Parts manual.
With pump switch ON and pressure turned to
MAXIMUM, use a test light to check for power
between clutch test points on control board.
Remove clutch wires from control board and
measure resistance across clutch coil. At 70°
F, the resistance must be between 1.2 + 0.2 ,
if not, replace pinion housing.
Have pressure control checked by authorized
Graco dealer.
Adjust or replace clutch. See Pinion Assem-
bly/Clutch Armature/Clamp, page 20.
Repair or replace pinion assembly. See Pinion
Assembly/Clutch Armature/Clamp, page 20.
334121B