TPI Speed Density Wiring Harness Installation
Using This Manual [show/hide]
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Click on [show/hide] of this or any other section to show or hide information.
Technical Questions? [show/hide]
Please send email to mike@s10wildside.com if you have any technical
questions.
Quality of Construction [show/hide]
This harness was constructed using OEM quality GXL wiring. The wire colors match the factory wire colors for a 1991
Camaro/Firebird TPI harness. Delphi terminals and connectors were used for connecting to the engine's sensors,
injectors, electronic control module (ECM), and other components. Delphi connectors are standard on GM original wiring
harnesses. All necessary solder connections are covered with heat shrink tubing.
What You Need [show/hide]
This harness is designed to work with a 1990-1992 style TPI engine and accessory configuration. The 1990-1992 style
engine is equipped with the following specific items that my not be found on earlier TPI engines:
- Fuel Pump Relay (GM# 14089936)
- Electric Fan Relay (GM# 14089936)
- Alternator (located on driver side)
- Small HEI Distributor with Externally Mounted Coil
- MAP Sensor (located on passenger side of plenum)
- Three Terminal Oil Pressure Switch
- Speed Density ECM (GM# 1227730)
- Knock Sensor (different than sensor used with earlier MAF system)
Installing the Harness [show/hide]
It is recommended that you first install the harness to the engine, then install the engine into your vehicle.
Using Your Vehicle's Existing Fuse Block
If you will not be using your vehicle's existing fuse block, please skip below to Fuse Block Installation.
If you are going to connect the harness to your vehicle's existing fuse block, then you will not need the included fuse
block. Cut the four wires that attach the included fuse block to the TPI wire harness. Connect the ORANGE wire to a 20 amp
battery power source in your vehicle's existing fuse block. Connect the PNK/BLK ECM Ignition Power wire to a 10 amp
ignition power source in your vehicle's existing fuse block (this must supply power with the key in the ON and CRANK position). Never connect any wire to a circuit that is protected by
a fuse that cannot handle the load. For example, don't add a 30 amp circuit to a circuit that is limited to 10 amps.
You will overload the circuit and blow fuses!
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| If your vehicle's fuse block does not have two additional 10
amp ignition power sources for the Injectors, you will have to use a relay (see diagram below) to power the Injectors. Connect any vehicle
ignition power source to the relay's coil high (86), a vehicle ground source to coil low (85), a battery power source to
the relay switch (30), and the PNK/BLK injector power wires to the relay contact (87). The Injector's PNK/BLK wires must
each use a 10 amp fuse in the circuit before connecting to the relay contact (87). When the relay receives a signal
from your vehicle's ignition source, the coil will switch power from the battery to energize the injectors.
I suggest use of the wiring diagrams for your specific vehicle if using your vehicle's fuse block. |
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Fuse Block Installation
If your vehicle's ignition power source cannot handle 30 amps, you will have to use a relay rated for up to
30 amps. Connect the igntion power from your vehicle (this must supply power with the key in the ON and CRANK position) to the relay's coil high (86), a vehicle ground source to coil low (85), a
battery power source to the relay switch (30), and the RED ignition wire from the supplied fuse block to the relay
contact (87). When the relay receives a signal from your vehicle's ignition source, the coil will switch power from the
battery to energize the injectors and ECM ignition power. |  |
Alternate Fuse Block Installation
Connect the ORANGE wire to a battery power source. This wire supplies constant power to the ECM, Fuel Pump Relay,
and Oil Pressure Switch. You must use a 20 amp fuse (included) in this circuit. Connect the RED wire to an ignition power source that supplies power with the key in the ON and CRANK position. This wire supplies ignition power to the fuel injectors and ECM.
Each bank of fuel injectors (set of four, one set on each side of engine) must use a 10 amp fuse (included) in the cirucit.
The ECM ignition power must also use a 10 amp fuse (included) in the circuit. |  |
Ground Wires
All the ground wires are terminated with two ring terminals and can be bolted to the back of the driver side head.
Also be sure to connect a Ground Strap (not included) from the Negative Battery Terminal to the Vehicle's Frame,
a Ground Strap from the Vehicle's Frame to the Engine, and a Ground Strap from the Engine to the Vehicle's Body. If
your vehicle is not properly grounded in this way, you will have wiring problems.
External Coil
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The PINK wire attached to the Gray External Coil connector, labeled "To Ingition Power", must be connected to the Ignition
Switch. From the factory, the Ignition Switch uses a Fusible Link (not included with this harness) in its circuit. The WHITE wire attached to the Gray External Coil connector, labeled "To Tach", may be connected to a tach
gauge. The Black External Coil connector must be connected to the Distributor's Ignition Module. |  |
Fuel Pump
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The ECM sends a signal to the Fuel Pump Relay to turn on the fuel pump. The GRAY wire labeled "To Fuel Pump" must be
connected to the positive fuel pump power wire to energize the fuel pump. |  |
Electric Fan
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The ECM sends a signal to the Fan Relay to turn on the electric fan when the engine reaches the temperature specified
in the ECM's PROM. The BLACK/RED wire labeled "To Electric Fan" must be connected to the positive electric fan wire to
energize the electric fan. The ORANGE wire coming from the Electric Fan Relay connector, labeled
"To Fusible Link, Then Battery", must be connected to the included 16 GA. Fusible Link, then to a Battery power source. |
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Alternator
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To allow the alternator to charge, the BROWN wire labeled "To Fusible Link, Then Ignition Power" must be connected to an
Ignition power source. A 20 amp fuse (included) must be used in this circuit. This BROWN wire is already tied into the
Electric Fan Relay to supply it power. The RED wire on the Alternator connector labeled "To Fusible Link, Then Battery Power"
must be connected to the included 16 GA. Fusible Link, then to a Battery power source. |  |
Oil Pressure Gauge
The TAN wire labeled "To Oil Pressure Gauge" should be connected to your oil pressure gauge. This wire is found connected
to the Oil Pressure Switch. Your Oil Pressure Gauge must be compatable with the GM Oil Pressure Sending Unit.
Speedometer
If you are using a Vehicle Speed Sensor (VSS), the GRAY wire labeled "Speed Output 4000 PPM" may be connected to the
Speedometer. You must use a Speedometer that requires a 4000 pulse per mile signal.
Cruise Control
The RED wire labeled "Speed Output 2000 PPM" may be connected to the Cruise Control Module. This wire sends a 2000 pulse
per mile signal from the ECM.
Air Conditioning
The connectors for the Air Conditioning are not included in this harness. You will have to use existing connectors and
splice the labeled GREEN and the GRAY wires from the ECM to the proper Air Conditioning components.
700R4 Transmission
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The PURPLE wire on the 700R4 transmission plug must be connected to the Brake Switch in your vehicle for proper Torque
Convertor Lockup operation. The ORANGE/BLACK wire coming from the ECM connector, labeled, "To Park/Neut Switch", must be
connected to a Park/Neutral Indicator Switch. This is not the same as a Neutral Safety Switch. The Park/Neutral Indicator
Switch is a switch that let's the ECM know if the vehicle is in Park or Neutral. A Neutral Safety Switch is a switch that
prevents the vehicle from starting unless it is in Park or Neutral. Be sure to connect the ORANGE/BLACK wire to a
Park/Neutral Indicator Switch. |  |
Vehicle Speed Sensor
The Vehicle Speed Sensor connector is not included in this harness. You will have to use an existing connector and
splice the PURPLE and the YELLOW wires from the ECM labeled "VSS" to a Vehicle Speed Sensor connector.
Upshift Indicator (Manual Transmission Only)
The TAN/BLACK wire coming from the Green ECM connector may be connected to the Upshift Indicator Telltale Light in the
vehicle's instrument cluster.
Service Engine Soon
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The BROWN/WHITE wire from the ECM connector labeled, "Service Engine Soon" may be connected to the Service Engine Soon
Telltale light in the vehicle's Instrument Cluster. The light is turned ON when the ECM grounds the circuit. |
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