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.
Injection Nozzles
The injection nozzles spray fuel into a prechamber on each compression stroke. A fuel return line connects all injectors and returns excess fuel to the pump. If spray patterns are incorrect, nozzles can be overhauled.
Injector opening pressures are adjustable. On I-Mark models, opening pressures can be adjusted by shim replacement. P'UP models use an adjustment screw in the injector nozzle.
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Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.