Toyota Supra 1990 Manual page 40

EM-8
1 1
EX
IN
1 1 4 4
ENGINE MECHANICAL - Engine Tune-Up
EM3008
EM3014
5 5
EM2890
(e) Disconnect following hoses:
• VSV hose (for EGR)
• BVSV hose
• EGR vacuum modulator hoses
• No.7 air hose
(f) Disconnect the throttle position sensor connector.
(g) Remove the throttle body brackets.
(h) Remove the air intake connector bracket mounting
bolts.
(i)
Remove the four bolts, two nuts, air intake connec-
tor and gasket.
4. REMOVE CYLINDER HEAD COVERS
(See step 15 on page EM-39)
5. MEASURE VALVE CLEARANCE
(a) Set No.1 cylinder to TDC/compression.
• Turn the crankshaft pulley and align its groove with
the "0" mark on the No.1 timing belt cover.
• Check that the valve lifters on the No.1 cylinder are
loose and valve lifters on the No.6 cylinder are tight.
If not, turn the crankshaft pulley one complete revolution.
(b) Measure the clearance of No.1 (IN) and No.4 (IN) and
No.1 (EX) and No.5 (EX) valves.
• Measure only those valves indicated in the figure.
• Record the measurements which are out of specifi-
cation. They will be used later to determine the re-
quired replacement shims.
Valve clearance (Cold):
Intake 0.15 - 0.25 mm (0.006 - 0.010 in.)
Exhaust 0.20 - 0.30 mm (0.008 - 0.012 in.)