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.
Intermittent Bucking & Jerking
1987 Ford Cutaway 6.9 1SECTION Intermittent Bucking & Jerking
- Check ignition system secondary wires, distributor cap and rotor, Thick Film Integrated (TFI) ignition module, engine spark, plug firing voltages, cylinder balance, and base ignition timing. Check spark plugs for fouling and proper gap.
- Perform QUICK TEST . Connect Manifold Absolute Pressure (MAP)/Barometric Pressure (BP) tester to MAP or BP sensor (depending on vehicle). Check readings with engine off and with ignition switch in "ON" position. Compare reading with MAP/BP SPECIFICATIONS table at end of article.
- On Vane Airflow Meter (VAF) equipped vehicles, check for unmetered air leaks. Check for loose air tubes, missing hoses, or vacuum plugs.
RENDER: 1.0x
NO RELATED
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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.