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CIH Engine - Bosch FI Conversion |
03.01.2002 | ||||||||||||||||||||
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Where do you start? What do you need? | ||||||||||||||||||||||
Converting the Opel CIH engine to FI (Bosch L- or LE-Jetronic) is not quite as daunting as it would seem. In the US, salvage yards can only be used as a source for the L-Jetronic system used on 1975 Opel models. LE or Motronic systems will have to be imported. Make sure to get all the required parts for the conversion, as listed below. Some parts are near impossible to get after the fact! | ||||||||||||||||||||||
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Fuel Line Routing: Yellow lines mark pressurized fuel lines, orange marks non-pressurized line back to tank. Hoses must be high quality and designed specifically for high pressure fuel injection (indicated on hose). A new line must be installed (at least 5/16” (~8mm) diameter) from pump at tank to engine room for pressurized fuel. Original nylon line (black or clear) may be used for flow back from engine compartment to tank and must be the same size as the pressure line so there's no restriction to fuel flow returning to the tank. | ||||||||||||||||||||||
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Fuel Pump Assembly - should
be mounted underneath rear of car as close as possible to the fuel tank.
Line from tank feeding pump should be enlarged to 1/2” (~12-13mm). Fuel
filter can either be mounted close to pump (shown) or in engine
compartment for easier access (recommended).
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General Information :
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Engine Compartment Wiring :
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Additional Installation
requirements: 1.
As FI thermostat housings have no
provision for heater hose connection, remove engine drain plug under
exhaust manifold near the oil pressure sender and replace with hose
connector removed from original FI engine to connect second 5/8” (16mm)
hot water hose from block to heater control valve. 2.
Original fuel pump is no longer used
and may be removed. Using the original fuel pump spacer as template,
fabricate and install a thick 1/4" (~6mm) metal plate to cover original
pump hole in the timing chain cover. 3. Wiring diagram doesn't show clearly that the green wire from the control unit should be connected to the negative (points/trigger - connection terminal 1 in wiring diagrams) terminal of the ignition coil.
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Adjustments: After installation, everything should now work. However, if idling is poor, mixture and idle speed can be adjusted. Check all rubber airway and vacuum hoses and connections for leaks before making any adjustments.
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Adjust idle speed (clockwise is slower) with a 15mm box end wrench and screwdriver
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Wiring Diagram (Bosch L-Jetronic): | ||||||||||||||||||||||
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Pin Outs - Dual Relay: |
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Wiring Diagram (LE-Jetronic): | ||||||||||||||||||||||
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1. ECU plug
strip |
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3. Temperature
sensor |
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4. Ground |
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5. Auxiliary Air
valve |
12. Control
relay |
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6. Throttle valve
switch |
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7. Air Flow
meter |
14. Fuel
pump |
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Pin Outs - Main Control Relay : |
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Wiring Diagram (LE-Jetronic with IAC): | ||||||||||||||||||||||
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Pin Outs - Main Control Relay : | ||||||||||||||||||||||
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