Holley 02121NOS - Manual (Page 18)

Figure 23 Exploded View of a Typical Solenoid
Appendix A Troubleshooting Guide
The troubleshooting chart on the following pages should help determine and rectify most problems with your installed NOS
system. If you still need assistance determining or fixing problems, call the NOS Technical Support at 1-866-GOHOLLEY.
PROBLEM POSSIBLE
CAUSES DIAGNOSTIC PROCEDURE CORRECTIVE ACTION
System wired
incorrectly. Compare wiring to schematic in Fig. 12. Wire per instructions.
Restricted fuel line. Inspect fuel line for restrictions (crimped
or plugged). Remove restrictions.
No change in engine
speed when the fuel
solenoid is activated
(Preparing for Operation—
Chapter 4).
Malfunctioning fuel
solenoid. Turn arming switch ON. Cycle the
microswitch. Solenoid should make
“clicking” noise. Repair/replace solenoid.
Change in engine speed
when nitrous bottle valve
is opened (Preparing for
Operation—Chapter 4). Malfunctioning nitrous
solenoid. Remove and inspect solenoid. Repair/replace solenoid.
Bottle valve not fully
opened. Check bottle valve. Open valve fully.
Bottle mounted
improperly. Check bottle orientation. Mount bottle properly.
Plugged nitrous filter. Inspect filter. Clean/replace filter.
Low bottle pressure. Check bottle temperature. Set bottle temperature to
75° to 85°F.
Engine runs rich when
system is activated.
Inadequate nitrous
supply. Weigh bottle. Fill bottle.
(1-800-99-REFILL)
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