Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1986 Jeep Comanche Custom, 2.5 H, 4WD, AutomaticFACTORY OEM SERVICE PROCEDURE
2.5L TBI System
- Description
- Operation
- Notes
- Electronic Control Unit (Ecu)
- Sensors & Switches
- Exhaust Gas Oxygen (EGO) Sensor
- Manifold Air/Fuel Temperature (MAT) Sensor
- Coolant Temperature Sensor (CTS)
- Manifold Absolute Pressure (MAP) Sensor
- Knock Sensor
- Speed Sensor
- Battery Voltage
- Starter Motor Relay
- Wide Open Throttle (WOT) Switch
- Closed Throttle (Idle) Switch
- Transmission Gear Position Indicator
- Power Steering Pressure Switch
- A/C Switch
- Fuel Control
- Emission Control
- Idle Speed Actuator (ISA)
- Ignition Advance Control
- Ecu-Controlled Relays
- Up-Shift Indicator Lamp
- Modes Of Operation
- Component Testing
- System Diagnosis
- Preliminary Checks
- Diagnostic Test Charts
- Chart 1 Ignition Switch Off
- Chart 2-A Ignition Switch On
- Chart 2-B Ignition Switch On (Cont.)
- Chart 2-C Ignition Switch On (Cont.)
- Chart 3 Throttle Position Sensor Test
- Chart 4-A System Operational Test
- Chart 4-B System Operational Test (Cont.)
- Chart 4-C System Operational Test (Cont.)
- Chart 4-D System Operational Test (Cont.)
- Chart 4-E System Operational Test (Cont.)
- Chart 4-F System Operational Test (Cont.)
- Chart 4-G System Operational Test (Cont.)
- Chart 4-H System Operational Test (Cont.)
- Chart 4-I System Operational Test (Cont.)
- Chart 4-J System Operational Test (Cont.)
- Chart 4-K System Operational Test (Cont.)
- Chart 5 Basic Engine Test
- Chart 6-A Man. Trans. Up-Shift Test
- Chart 6-B Man. Trans. Up-Shift Test (Cont.)
- Removal & Installation
- Throttle Body Assembly
- Fuel Injector
- Fuel Pressure Regulator
- Idle Speed Actuator (ISA), Motor & Wide Open Throttle (Wot) Switch
- Electronic Control Unit
- Oxygen Sensor
- Manifold Air Temperature (Mat) & Manifold Absolute Pressure (Map) Sensors
- Coolant Temperature Sensor (Cts)
- EGR Valve & Canister Purge Solenoid
- Adjustments
- Wiring Diagrams
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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