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.
1991 Suzuki Samurai JSFACTORY OEM SERVICE PROCEDURE
Poor Fuel Mileage
- Check for fuel leaks.
- Check for clogged air filter.
- Check compression.
- Check fuel pressure.
- Check cooling system.
- Check ignition and valve timing.
- Check spark plugs.
- Check for faulty throttle position sensor (if equipped).
- Check for faulty coolant (water) temperature sensor.
- Check for faulty ECM.
- Check for high idle RPM.
- Check for malfunctioning electronic fuel injection system.
- Check for malfunctioning distributor mechanical and vacuum advance (if equipped).
- Check for malfunctioning EGR valve (if equipped).
- Ensure sufficient secondary spark is available.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.