Inspection And Adjustment Of Idle Mixture; Initial Conditions; Inspect And Adjust Idle Co Concentration; Method With Co Meter - Toyota 7M-GE Repair Manual

ENGINE MECHANICAL! Y) Engine Tune-up
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-INSPECTION AND ADJUSTMENT OFIDLE
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MIXTURE (w/o TWC)
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tNSPECT AND ADJUST IDLE CO CONCENTRATION
120 Seconds
Tachometer
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EC016
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INITIAL CONDITIONS
(a) Ajr cleaner Jnstalled
(b) Normal engine operating temberature
(cf All pipes and hoses of air intake system connected
(d) All accessories switched off
'6) All vacuum lines properly connected
(f) EFI system~'w&g connectors fully plugged
c(g) I.gnitio$ timing set correctly
(h) Transmission. i.n,.N range
CONNECT TACHCBMETER TO ENGINE
(See page EM-171
CHECK IDLE SPEED
Idle speed: 800 rpm
CAUTION:
a Always use a CO meter,.,when adjusting the idle mix-
ture. It is not necessary to adjust with the idle mix-
ture adjusting screw in. most vehicles if they are in
good condition. If a CO meter is not available, DO
NOT ATTEMPT TO ADJUST WITH THE SCREW.
l
If a CO meter is not available and it is absolutely
necessary to adjust with the idle mixture adjusting
screw, or if the air flow meter is replaced, use the
alternative method.
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METHOD WITH CO METER
(a) Check that the CO meter is properly calibrated.
(b) Race the engine for approx. 120 seconds at appr 1,
2,500 rpm before measuring the concentration.
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(c) Wait
1 - 3 minutes after racing the engine to allow
the concentration to stabilize.
(df Insert a testing probe at least 40 cm (1.3 ft) into the
tailpipe, and measure the concentration with a short
time.
Idle
CO concentration: 1.0 -t- 0.5 %