Nilfisk-Advance 56507009, Troubleshooting Manual

Page: 29 / 82

FORM NO. 56043129 - SR 1900 - 29
Troubleshooting Guide
Symptom
Part 2: Diesel engine will crank but not start
Note: Always use (activate) the glow plugs circuit to start an engine that is not up to its operating
temperature. Note 1: Before troubleshooting inspect the 10A CB5 circuit breaker, replace if defective.
Note 2: The engine uses a low oil pressure shut down feature. Check to see that the engine oil fill
level is correct. As no oil will prevent the engine from starting, for its own protection (5PSI) is min.
pressure to open switch S28 for engine to start.
Diesel engine will crank but not
start Governor/ Actuator T.S.
W/engine cranking test
for 12V’s @ the governor
speed select #2 terminal.
Is there 12V’s ?
No
Replace oil pressure SW
& reconnect all wiring
does engine run? If yes
the oil pressure switch
was defective.
Test for 12V @ the Apec
3000 governor battery
input (Pos & Neg. )
terminals.
Test the key Sw accessory
output & circuit wiring to
governor. Repair or replace
defective parts.
Test the fuel control actuator for an open (spec is 3.5 Ohms). If
defective replace. Reinstall the actuator. Does engine start?
Check the governor magnetic pickup voltage signal, w/engine cranking
(approx. 1.2 -3.7 VAC). If no signal substitute a good known magnetic
pickup sensor. Does engine run?
Note: (*)Test engine oil
pressure if below min. spec
investigate its cause and
make needed repairs.
Re-test w/engine
cranking. Is there
12V’s @ speed select
#2 terminal?
If the S28 oil pressure
switch does not receive
its min. oil pressure to
open (5psi) investigate
further engine oil
pressure problems &
make repairs (*).
1. Remove the (2) screws that fasten the fuel control actuator then
remove from injector pump. 2. Try starting the engine it should start with
actuator removed. Important operator note: When engine starts it could
run @ full speed. To stop engine pull DN on the engine stop lever to
prevent over revving damage to engine. Does engine start?
Remove the governor magnetic pickup sensor inspect for damage &
also that the pickup is installed with the correct clearance. Thread
sensor in until it makes contact with the flywheel then back it out a ½
turn. Does engine start?
Substitute a good known working governor. Does engine run?
1. See fuel system T.S. (part 1) 2. See engine service manual no start
fuel injector pump system
No
No
Yes
Yes
Yes
No
Yes
No
ENGINE SYSTEM
TROUBLESHOOTING GUIDE