Honda Acura NSX 1991, Service Manual

Page: 986 / 1420

Pressure Test
NOTE: Performance Test on page 22-96.
TFCT
II
PROBABLE CAUSE R E M E D Y
Discharge (high)
After stopping compressor, pressure Air in system
Evacuate system: then
pressure abnormally
drops to about 196 psi) recharge
quickly, and then falls gradually Evacuation: page 22-93
Recharging: page 22-95
No bubbles in sight glass when Excessive refrigerant in Discharge refrigerant as
denser is cooled by water system necessary
Reduced or no air flow through
l
Clogged condenser or radiat-
l
Clean
denser.
er fins
l
Condenser or radiator fan not
l
Check voltage and fan rpm
working properly
Line to condenser is excessively hot Restricted flow of refrigerant E x p a n s i o n v a l v e
in system
Discharge pressure
abnormally low
Suction
pressure abnormally
l o w
Suction pressure
abnormally high
Suction and
discharge pressures
abnormally high
Suction and
discharge pressure
abnormally low
Refrigerant leaks
Excessive bubbles in sight glass; insufficient refrigerant in
l
Check for leak
condenser is not hot
system
l
Charge system
High and low pressures are balanced
l
Faulty compressor discharge Replace compressor
soon after stopping compressor
o r i n l e t v a l v e
l
Faulty compressor seal
Outlet of expansion valve is not
l
Faulty expansion valve Replace
frosted, low pressure gauge indi-
cates vacuum
Excessive bubbles in sight glass;
Insufficient refrigerant Check for leaks.
condenser is not hot
Charge as required.
Expansion valve is not frosted and
l
F r o z e n e x p a n s i o n v a l v e Replace expansion valve
low pressure line is not cold. Low
l
Faulty expansion valve
pressure gauge indicates vacuum
Discharge temperature is low and Frozen evaporator
Run the fan with compressor
the air flow from vents is restricted
off then check capillary tube.
Expansion valve frosted Clogged expansion valve Clean or Replace
Receiver dryer is cool (should be Clogged receiver dryer Replace
warm during operation)
Low pressure hose and check joint
l
Expansion valve open too long
Repair or Replace.
are cooler than around evaporator
l
L o o s e e x p a n s i o n v a l v e
Suction pressure is lowered when Excessive refrigerant in
Discharge refrigerant as
condenser is cooled by water system
necessary
High and low pressure are equalized
l
Faulty gasket
Replace compressor
as soon as the compressor is
l
Faulty high pressure valve
stopped
l
Foreign particle stuck in high
p r e s s u r e v l a v e
Reduced air flow through condenser
l
Clogged condenser or radiator
l
Clean condenser and radiator
fins
l
Check voltage and fan rpm
l
Condenser or radiator fan not
working properly
No bubbles in sight glass when Excessive refrigerant in Discharge refrigerant as
denser is cooled by water
system necessary.
Low pressure hose and metal end
Clogged or kinked low Repair or Replace
areas are cooler than evaporator sure hose parts
Temperature around expansion valve Clogged high pressure line Repair or Replace
is too low compared with that
around receiver-dryer
Compressor clutch is dirty Compressor shaft seal leaking Replace compressor
Compressor bolt(s) are dirty Leaking around Tighten bolt(s) or replace
compressor
Compressor gasket is wet with oil
Gasket leaking Replace compressor
22-98