length VOLKSWAGEN CORRADO 1990 Repair Manual

1.8L 4-CYL 8-VALVE & 1.8L 4-CYL 16-VALVE
Article Text (p. 23)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:40PM
Oil Ring
End Gap ........................ .010-.018 (.25-.45).
Side Clearance .................. .001-.002 (.02-.05)
(1) - Wear limit is .04" (1.0mm).
(2) - Wear limit is .006" (.15mm).ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ CRANKSHAFT MAIN & CONNECTING
ROD BEARINGS SPECIFICATIONS
CRANKSHAFT MAIN & CONNECTING
ROD BEARINGS SPECIFICATIONS TABLE
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication In. (mm)
1.8L
Crankshaft
Crankshaft End Play (1) ............ .003-.007 (.07-.17)
Runout ........................................... .....
Journal Taper .................................... .....
Journal Out-Of-Round ........................ .001 (.03)
Main Bearings
Journal Diameter ............. 2.124-2.125 (53.96-53.98)
Oil Clearance (2) .................. .001-.003 (.02-.07)
Connecting Rod Bearings
Journal Diameter ............. 1.880-1.881 (47.76-47.78)
Oil Clearance (3) ......................... .0049 (.124)
(1) - Wear limit is .010" (.25mm).
(2) - Wear limit is .007" (.17mm).
(3) - Maximum allowable clearance.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ CONNECTING ROD SPECIFICATIONS
CONNECTING ROD SPECIFICATIONS TABLE
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication In. (mm)
1.8L
Side Play (1) ............................... .015 (.38)
Maximum Bend & Twist ............................. .....
Pin Bore Diameter ......................... .787 (19.98)
Large Bore Diameter ...................... 1.992 (50.59)
Center-to-Center Length ................. 5.669 (143.99)
(1) - Maximum allowable limit.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ CYLINDER HEAD SPECIFICATIONS

1.8L 4-CYL 8-VALVE & 1.8L 4-CYL 16-VALVE
Article Text (p. 25)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:40PM
8-Valve Exhaust ...................... 1.300 (33.02)
8-Valve Intake (2) ................... 1.575 (40.00)
8-Valve Exhaust ...................... 1.229 (31.21)
16-Valve (3) ......................... 1.102 (27.99)
Stem Diameter
8-Valve ................................ .314 (7.97)
16-Valve ............................... .273 (6.93)
Face Angle ....................................... 45ø Maximum Refinish
8-Valve Intake (4) ................... 3.583 (91.00)
8-Valve Exhaust (4) .................. 3.574 (90.77)
8-Valve Intake (4) ................... 3.886 (98.70)
8-Valve Exhaust (4) .................. 3.878 (98.50)
16-Valve (4) ......................... 3.866 (98.19)
(1) - These specifications apply to engines with code
UM.
(2) - These specifications apply to engines with codes
GX, JH, PF and RV.
(3) - These specifications apply to engines with code
PL. Specifications apply to both intake and
exhaust valves.
(4) - Specification is standard valve length.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ CAMSHAFT SPECIFICATIONS
CAMSHAFT SPECIFICATIONS TABLE
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication In. (mm)
Oil Clearance ................................. .004 (.10)
End Play ...................................... .006 (.15)
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄEND OF ARTICLE

A/C-HEATER SYSTEM - MANUAL
Article Text (p. 7)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
3) Check for cool air from left duct. Low-pressure gauge
should read more than 16 psi (1.1 kg/cmý). If low-pressure gauge is
incorrect, hold hands around expansion valve to warm valve. If
pressure rises, moisture is present in system. Discharge using
approved refrigerant recovery/recycling equipment. Evacuate and
recharge system. If pressure does not rise, go to next step.
4) Check temperature on thermometer when thermostatic switch
turns compressor off. If temperature is 39
øF (4øC), system is okay. If
lower than 39
øF (4øC), ensure capillary tube installed length is 7"
(178 mm). If installation is correct, replace thermostatic switch.
REMOVAL & INSTALLATION
NOTE: Removal and installation procedures on other models or
components are not available from manufacturer.
EVAPORATOR - VANAGON
1) Discharge refrigerant from system using approved
refrigerant recovery/recycling equipment. Remove sun visors and sun
visor retaining clips. Lower front housing and front air duct.
2) Disconnect wiring connectors to A/C switches. Remove front
housing, front air ducts, center air duct, rear air duct, left side
rear trim panel and right side rear trim panel.
3) Support evaporator housing. Remove left and right side
evaporator housing mounting screws. Lower evaporator housing. Remove
evaporator housing covers. Remove evaporator. See Fig. 4. To install,
reverse removal procedure. Evacuate and recharge system.Fig. 4: Exploded View of Evaporator Assembly (Vanagon)
Courtesy of Volkswagen United States, Inc.
A/C SYSTEM SPECIFICATIONS

E - THEORY/OPERATION - DIGIFANT
Article Text (p. 6)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:43PM
element and the power steering pressure switch.
FUEL PRESSURE REGULATOR
The fuel pressure regulator is a sealed, spring loaded
diaphragm with connection for intake manifold vacuum. Fuel pressure is
maintained at about 36 psi (2.5 kg/cmý) pressure.
A connection for intake manifold vacuum provides a constant
pressure differential which ensures that the amount of fuel injected
is solely dependent upon injector open ON time. Excess fuel is
returned to fuel tank. No service of pressure regulator is required.
The pressure regulator is located on or near fuel rail.
FUEL CONTROL
Data on engine temperature, engine speed, intake air volume,
throttle position, exhaust oxygen content and intake air temperature
are used by ECM to determine injection pulse width.
FUEL INJECTORS
A fuel rail links the fuel pressure regulator with the fuel
injectors. Each cylinder is provided with a solenoid-operated injector
which sprays fuel toward backside of each inlet valve. Each injector
is energized through the ignition coil and grounded through the ECU to
complete the circuit
Each injector is linked to a resistor (resistor may be
external or integral with injector or ECU) to reduce operating voltage
to 3 volts and to protect injectors from power surges. The ECU
controls length of time each injector is open. The ON time of the
injector governs the amount of fuel delivered. The injector delivers
1/2 the amount of fuel required for an operating cycle each time they
open (twice per cycle).
FUEL PUMP AFTER-RUN RELAY (CORRADO)
The purpose of the After-Run Fuel Pump relay system is to
reduce the chance of fuel vaporizing in fuel rail. Both transfer pump
and fuel pump are used to recirculate fuel. The after-run relay
switches the pumps on for 2 minutes after ignition is turned off or
when under hood temperature exceeds 194
ø F (90ø C) and fuel pressure
is above 17 psi (1.2 kg/cm
ý). The pumps operate a maximum of 8
minutes.
IDLE SPEED
Engine idle speed is controlled by the ECU and idle speed
control unit depending upon engine operating conditions. The ECU and
Idle speed control unit are fed information on engine operating
conditions and determine the best idle speed.
IDLE AIR STABILIZER VALVE

ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION
Article Text (p. 4)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PM
specifications for the vehicle being repaired.
SHEET METAL PARTS
Examples of sheet metal parts are the rocker covers, front
and side covers, oil pan and bellhousing dust cover. Glass bead
blasting or hot tank may be used for cleaning.
Ensure all mating surfaces are flat. Deformed surfaces should
be straightened. Check all sheet metal parts for cracks and dents.
INTAKE & EXHAUST MANIFOLDS
Using solvent cleaning or bead blasting, clean manifolds for
inspection. If the intake manifold has an exhaust crossover, all
carbon deposits must be removed. Inspect manifolds for cracks, burned
or eroded areas, corrosion and damage to fasteners.
Exhaust heat and products of combustion cause threads of
fasteners to corrode. Replace studs and bolts as necessary. On "V"
type intake manifolds, the sheet metal oil shield must be removed for
proper cleaning and inspection. Ensure that all manifold parting
surfaces are flat and free of burrs.
CYLINDER HEAD REPLACEMENT
* PLEASE READ THIS FIRST *
NOTE: Always refer to appropriate engine overhaul article in the
ENGINES section for complete overhaul procedures and
specifications for the vehicle being repaired.
REMOVAL
Remove intake and exhaust manifolds and valve cover. Cylinder
head and camshaft carrier bolts (if equipped), should be removed only
when the engine is cold. On many aluminum cylinder heads, removal
while hot will cause cylinder head warpage. Mark rocker arm or
overhead cam components for location.
Remove rocker arm components or overhead cam components.
Components must be installed in original location. Individual design
rocker arms may utilize shafts, ball-type pedestal mounts or no rocker
arms. For all design types, wire components together and identify
according to the corresponding valve. Remove cylinder head bolts.
Note length and location. Some applications require cylinder head
bolts be removed in proper sequence to prevent cylinder head damage.
See Fig. 1. Remove cylinder head.

ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION
Article Text (p. 6)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PM
Some models require hydraulic lifter to be bled down and
clearance measured. Different length push rods can be used to obtain
proper clearance. Clearance will be checked between tip of rocker arm
and tip of valve stem in proper sequence using a feeler gauge.
On overhead cam engines designed without rocker arms actuate
valves directly on a cam follower. A hardened, removable disc is
installed between the cam lobe and lifter. Clearance will be checked
between cam heel and adjusting disc in proper sequence using a feeler
gauge. Engine will be rotated to obtain all valve adjustments.
On overhead cam engines designed with rocker arms, adjustment
is made at push rod end of rocker arm. Ensure that the valve to be
adjusted is riding on the heel of the cam on all engines. Clearance
will be checked between tip of rocker arm and tip of valve stem in
proper sequence using a feeler gauge. Adjustment is made by rotating
adjusting screw until proper clearance is obtained. Lock nut is then
tightened. Engine will be rotated to obtain all valve adjustments to
manufacturer's specifications.
CYLINDER HEAD OVERHAUL
* PLEASE READ THIS FIRST *
NOTE: Always refer to appropriate engine overhaul article in the
ENGINES section for complete overhaul procedures and
specifications for the vehicle being repaired.
DISASSEMBLY
Mark valves for location. Using valve spring compressor,
compress valve springs. Remove valve locks. Carefully release spring
compressor. Remove retainer or rotator, valve spring, spring seat and
valve. See Fig. 2.Fig. 2: Exploded View of Intake & Exhaust Valve Assemblies - Typical
This Graphic For General Information Only

ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION
Article Text (p. 7)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PM
CLEANING & INSPECTION
Clean cylinder head and valve components using approved
cleaning methods. Inspect cylinder head for cracks, damage or warped
gasket surface. Place straightedge across gasket surface. Determine
clearance at center of straightedge. Measure across both diagonals,
longitudinal centerline and across the head at several points. See
Fig. 3.Fig. 3: Checking Cylinder Head for Warpage - Typical
This Graphic For General Information Only
On cast cylinder heads, if warpage exceeds .003" (.08 mm)
in a 6" span, or .006" (.15 mm) over total length, cylinder head must
be resurfaced. On most aluminum cylinder heads, if warpage exceeds .
002" (.05 mm) in any area, cylinder head must be resurfaced. Warpage
specification may vary with manufacturer.
Cylinder head thickness should be measured to determine
amount of material which can be removed before replacement is
required. Cylinder head thickness must not be less than manufacturer's
specifications.
If cylinder head required resurfacing, it may not align
properly with intake manifold. On "V" type engines, misalignment is
corrected by machining intake manifold surface that contacts cylinder
head. Cylinder head may be machined on surface that contacts intake
manifold.
Using oil stone, remove burrs or scratches from all sealing
surfaces.
VALVE SPRINGS
Inspect valve springs for corroded or pitted valve spring
surfaces which may lead to breakage. Polished spring ends caused by
a rotating spring, indicates that spring surge has occurred. Replace
springs showing evidence of these conditions.
Inspect valve springs for squareness using a 90 degree
straightedge. See Fig. 4. Replace valve spring if out-of-square
exceeds manufacturer's specification.

ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION
Article Text (p. 8)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PMFig. 4: Checking Valve Spring Squareness - Typical
This Graphic For General Information Only
Using vernier caliper, measure free length of all valve
springs. Replace springs if not within specification. Using valve
spring tester, test valve spring pressure at installed and compressed
heights. See Fig. 5.
Usually compressed height is installed height minus valve
lift. Replace valve spring if not within specification. It is
recommended to replace all valve springs when overhauling cylinder
head.Fig. 5: Checking Valve Spring Pressure - Typical
This Graphic For General Information Only
VALVE GUIDE
Measuring Valve Guide Clearance
Check valve stem-to-guide clearance. Ensure valve stem
diameter is within specifications. Install valve in valve guide.
Install dial indicator assembly on cylinder head with tip resting
against valve stem just above valve guide. See Fig. 6.

ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION
Article Text (p. 9)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PMFig. 6: Measuring Valve Stem-to-Guide Clearance - Typical
This Graphic For General Information Only
Lower valve approximately 1/16" below valve seat. Push valve
stem against valve guide as far as possible. Adjust dial indicator to
zero. Push valve stem in opposite direction and note reading.
Clearance must be within specification.
If valve guide clearance exceeds specification, valves with
oversize stems may be used or valve guide must be replaced. On some
applications, a false guide is installed, then reamed to proper
specification. Valve guide reamer set is used to ream valve guide to
obtain proper clearance for new valve.
Reaming Valve Guide
Select proper reamer for valve stem. Reamer must be of
proper length to provide clean cut through entire length of valve
guide. Install reamer in valve guide and rotate to cut valve guide.
See Fig. 7.Fig. 7: Reaming Valve Guides - Typical
This Graphic For General Information Only

ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION
Article Text (p. 17)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PM
Install stud protectors on connecting rod bolts. This protects
cylinder walls from scoring during removal. Ensure proper removal of
ridge. Push piston and connecting rod from cylinder. Connecting rod
boss can be tapped with a wooden dowel or hammer handle to aid in
removal.
PISTON & CONNECTING ROD
Disassembly
Using ring expander, remove piston rings. Remove piston pin
retaining rings (if equipped). On pressed type piston pins, special
fixtures and procedures according to manufacturer must be used to
remove piston pins. Follow manufacturer's recommendations to avoid
piston distortion or breakage.
Cleaning
Remove all carbon and varnish from piston. Pistons and
connecting rods may be cleaned in cold type chemical tank. Using ring
groove cleaner, clean all deposits from ring grooves. Ensure all
deposits are cleaned from ring grooves to prevent ring breakage or
sticking. DO NOT attempt to clean pistons using wire brush.
Inspection
Inspect pistons for nicks, scoring, cracks or damage in ring
areas. Connecting rod should be checked for cracks using Magnaflux
procedure. Piston diameter must be measured in manufacturers specified
area.
Using telescopic gauge and micrometer, measure piston pin
bore of piston in 2 areas, 90 degrees apart. This is done to check
diameter and out-of-round.
Install proper bearing cap on connecting rod. Ensure bearing
cap is installed in proper location. Tighten bolts or nuts to
specification. Using inside micrometer, measure inside diameter in 2
areas, 90 degrees apart.
Connecting rod I.D. and out-of-round must be within
specification. Measure piston pin bore I.D. and piston pin O.D. All
components must be within specification. Subtract piston pin diameter
from piston pin bore in piston and connecting rod to determine proper
fit.
Connecting rod length must be measured from center of
crankshaft journal inside diameter to center of piston pin bushing
using proper caliper. Connecting rods must be the same length.
Connecting rods should be checked on an alignment fixture for bent or
twisted condition. Replace all components which are damaged or not
within specification.
PISTON & CYLINDER BORE FIT
Ensure cylinder is checked for taper, out-of-round and
properly honed prior to checking piston and cylinder bore fit. See
CYLINDER BLOCK in this article. Using dial bore gauge, measure
cylinder bore. Measure piston at right angle to piston pin in center