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.
1989 Plymouth Colt BaseFACTORY OEM SERVICE PROCEDURE
Throttle Position Sensor/Switch: PFI
- Loosen accelerator cable tension. Disconnect TPS wire harness and install Test Harness (MD998464). Connect DVOM to terminal No. 4 (Blue Clip on harness) and terminal No. 2 (Red clip) of the TPS.
- Turn ignition switch to "ON" position. DVOM should read .48-.52 volt. If reading is outside this range, loosen TPS and turn until correct reading is obtained. Tighten TPS. Turn ignition switch to "OFF" position. Remove test harness.
- Start engine. Check idle speed (600-800 RPM). Turn ignition off. Disconnect battery for 5 seconds or more. Adjust accelerator cable. Restart engine and allow to idle for 5 minutes or more.
Factory Service Tools
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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.