Tools & consumables
- Service manual or OEM specs (plug type, gap, torque). Verify engine is petrol — diesel engines have no spark plugs.
- New spark plugs (correct part number/heat range; recommended NGK/Denso/Champion). Replace 1 plug per cylinder.
- Replacement ignition coil boots/seals or full coil packs if worn (recommended inspection; replace if cracked/soft/leaking).
- 3/8" or 1/2" drive ratchet, extensions (4–10"), universal joint.
- Spark plug socket (magnetic or rubber insert) sized for your plugs (usually 5/8" (16mm) or 13/16"/21mm; metric may apply).
- Torque wrench (in-lb/Nm ranges).
- Spark plug gap tool (feeler or round-wire).
- Compressed air or vacuum.
- Dielectric grease (silicone) for coil boots.
- Anti-seize compound (only if manufacturer permits — most modern plugs are pre-coated; use sparingly if used).
- Small brush cloth, penetrating oil (for stuck coils), safety glasses, nitrile gloves.

Safety first
- Work on a cold engine. Hot heads risk burning and incorrect torque.
- Park on level ground, set parking brake, keys removed. Disconnect negative battery terminal if you’ll be working near wiring or for extra safety.
- Eye protection when blowing debris.
- Avoid open flames/ sparks when working near fuel system.

Quick notes before starting
- Mazda BT-50 / Ford Ranger share platforms; engines vary. Confirm petrol engine and exact plug specs (type, reach, gap, torque) from the manual.
- Modern Rangers/BT-50 often use coil-on-plug (COP) assemblies — you remove the coil to access the plug.
- If cylinder head is aluminum, extra care with torque and cross-threading is critical.

Step-by-step workshop procedure

1) Prep
- Gather tools and new plugs. Check the service manual for required plug part number, gap, and torque.
- Let engine cool fully (several hours or overnight).
- Disconnect negative battery terminal (optional but recommended).

2) Access
- Remove engine cover(s) if fitted: usually popped off or bolted.
- Locate ignition coils atop each spark plug well. Clean the top of the engine around each coil with compressed air/vacuum to remove dirt — prevents debris falling into plug holes.

3) Remove coils
- Unclip electrical connector from the coil. Depress the tab, pull straight out.
- Remove any retaining bolt(s) on the coil (typically 8mm). Keep bolts in order.
- Wiggle/pull the coil straight up. If stuck, spray a little penetrating oil at the boot base, wait, then rock the coil gently. Use a coil puller tool if needed.
- Inspect coil boot and seal for cracks, oil intrusion, carbon scoring. Replace coil/boot if damaged.

4) Remove spark plug
- Select correct spark plug socket with rubber/magnetic insert to hold plug.
- Attach extension and universal joint as required to reach angled holes.
- Insert socket into well, seat on plug carefully, and turn counterclockwise. Break initial torque gently — if very tight, stop and reassess (penetrating oil not for plugs in aluminum heads; be cautious).
- Remove plug by hand via socket. Inspect for signs of oil, coolant, heavy carbon, or electrode wear.

5) Inspect old plug
- Normal wear: tan/light brown insulator and electrode. Black, oily, or white glazed deposits indicate issues (oil burning, fuel mixture too rich/lean, cooling problem).
- Note condition for diagnosis.

6) Prepare new plug
- Verify plug type, reach length, and gap against OEM spec.
- Check gap: set to spec with a gap tool. Most modern iridium plugs are pre-gapped but verify.
- If manufacturer prohibits anti-seize, do NOT apply. If allowed and used, apply a very thin film to threads only — DO NOT get on the electrode or tip.
- For aluminum heads some manuals explicitly forbid anti-seize because plating adjusts torque calculations.

7) Install new plug
- Start threading by hand using the socket to avoid cross-threading. Hand-thread fully several turns before using ratchet.
- Once hand-seated, use torque wrench and tighten to OEM torque. Typical ranges (confirm manual):
- M12 plugs: ~20–30 Nm (15–22 ft-lb)
- Some longer-reach or larger plugs: ~25–35 Nm (18–26 ft-lb)
- If you lack a torque wrench, tighten gently until snug and then 1/16 to 1/8 turn more for new plugs — this is less accurate; get a torque wrench for proper work.

8) Reinstall coils
- Apply a small smear of dielectric grease inside the boot (not on the plug electrode) to help seal and ease removal later.
- Seat the coil squarely on the plug, press down until it clicks or seats fully.
- Reinstall coil retaining bolt(s) and torque to small spec (usually low Nm, check manual).
- Reconnect electrical connector.

9) Reassemble and test
- Reinstall engine cover.
- Reconnect negative battery if disconnected.
- Start engine and listen for smooth idle. Check for misfire codes or roughness.
- Road test briefly. After first drive, re-check coil bolts and ensure no check-engine lights.

Common pitfalls & how to avoid them
- Working on a diesel: no spark plugs — check engine type first.
- Cross-threading: always start by hand. Cross-threading aluminum head threads is expensive to repair.
- Over-torquing: strips or breaks threads in aluminum. Use a torque wrench and the correct spec.
- Using wrong plug reach: too long can hit the piston; too short reduces heat transfer — always use the specified plug.
- Not cleaning well: debris in the well falls into combustion chamber; blow out before removing plugs.
- Using too much anti-seize: will alter torque readings and can result in over-tightening. Most OEM plugs don’t need anti-seize.
- Reusing worn coil boots: leads to misfires. Replace boots if hardened or cracked.
- Ignoring plug condition: oil/fuel deposits indicate other engine issues — don’t just replace plugs and ignore root causes.

Tool usage details
- Spark plug socket: use the rubber/magnetic insert to hold the plug while removing/installing. Use extension and universal joint for angled access. Keep the socket perfectly centered on the plug to avoid rounding.
- Torque wrench: set to the specified torque, snug the extension and socket assembly on the plug and apply steady force until it clicks or indicates. For small torque values, use a 3/8" torque wrench rated for that range.
- Gap tool: use round-wire or feeler gauge. Bend the ground electrode gently, not the center electrode. Check both new and old to confirm wear.
- Compressed air: blow around coil and well before removal. Hold nozzle near edge, not deep into hole.

Replacement parts recommended
- New spark plugs (correct OEM spec/type: e.g., NGK/ Denso iridium or OEM specified). Replace all plugs at once.
- Ignition coils or individual coil boots if cracked, oily, or carbon-tracked.
- Coil mounting bolts and seals/gaskets if damaged.

Typical service intervals
- Depends on plug type: iridium/platinum ~60k–100k km; copper shorter (20k–40k km). Follow owner/service manual.

Final check
- Clear any stored fault codes after replacement if present; then verify none reoccur.
- Monitor engine performance for a few days for intermittent misfires.

Done.
rteeqp73

▶️TPS Test & Replace: Ford Ranger/Mazda B-Series🔧 TPS Test & Replace: Ford Ranger/Mazda B-Series .Easy how to test to see if your Throttle Positioning Sensor is functioning ...

Ford Ranger / Mazda B2500 gearbox info, senor locations, fill plug. ect R15-MXD transmission.

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