Login to enhance your online experience. Login or Create an Account
Logo
Shopping Cart

Shopping Cart 0 Items (Empty)

Toyota 2H and 12H-T digital engine factory workshop and repair manual

Quick note: there are two different “fuel pumps” on these older Toyota diesels — the low‑pressure lift (transfer) pump that feeds the injection pump, and the high‑pressure injection pump that times and meters fuel to the injectors. Both are covered below. Follow safety steps exactly. No questions.

Safety first (do before any work)
- Wear eye protection, nitrile or mechanic gloves, and long sleeves to keep diesel off skin.
- Work in a well‑ventilated, fire‑safe area. No open flames, sparks, or smoking.
- Disconnect the negative battery terminal before working on fuel system to avoid accidental cranking.
- Have a fire extinguisher rated for fuel nearby and absorbent rags/containers for spills.
- Use jack stands on level ground if you need to lift the vehicle — never rely on a jack alone.

Tools you will need (detailed descriptions and how to use each)
- Socket set with ratchet and extensions (metric): used to remove nuts and bolts. Select the correct socket size, push it fully onto the fastener, and turn the ratchet handle clockwise to tighten or counterclockwise to loosen. Use extensions to reach deep bolts. Keep sockets perpendicular to avoid rounding bolts.
- Combination wrenches (metric, open and box end): used where a socket won’t fit. Use the box end on stubborn bolts; pull the wrench toward you rather than push to reduce slipping.
- Flare‑nut (fuel line) wrenches: these are thin, multi‑sided wrenches that grip fuel line fittings without rounding them. Always use these on fuel line nuts; place the wrench fully over the nut and turn slowly.
- Torque wrench (click‑type, appropriate range e.g., 5–100 Nm or 10–150 ft‑lb): used to tighten bolts to the manufacturer specified torque. Set the torque, apply steady force until it clicks, then stop. This prevents crushes, leaks, and broken studs.
- Screwdrivers (flat and Phillips): for clamps, small screws, prying small covers. Use the correct size tip to avoid cam‑out.
- Pliers (slip‑joint, needle‑nose): for clamps, cotter pins and hoses. Needle‑nose for tight spaces; use slip‑joint for stronger grip but not for nuts.
- Drain pan or container: to catch diesel from lines or pump. Keep a lid or absorbent pads to contain spills.
- Clean rags and parts cleaner (degreaser): to clean surfaces and remove diesel residue before fitting new parts.
- Gloves and eye protection: repeated for emphasis — protect hands and eyes from fuel and debris.
- Hand‑held vacuum priming pump or manual fuel primer (recommended): helps bleed air from fuel lines quickly by pulling fuel through without cranking the engine.
- Small pick set and gasket scraper: remove old gaskets and O‑rings cleanly without gouging mating surfaces.
- Wire brush and scotch‑brite pad: clean mating surfaces and bolt threads.
- Replacement crush washers or copper washers (banjo bolts): these seal fuel fittings; always replace when separating lines.
- New gaskets and O‑rings specific to the pump: prevent leaks; old compressible gaskets rarely reseal reliably.
- Brake cleaner / diesel‑safe solvent: for final cleaning.
- Service manual or printout with torque specs and timing marks (strongly recommended): provides exact numbers and engine timing procedure.

Additional tools you may need (why they’re required)
- Injection pump timing pin / locking tool: needed to lock the engine and injection pump to the correct timing position while removing/installing a high‑pressure injection pump. Without it you can lose timing and damage the engine.
- Dial indicator or degree wheel (for advanced injection pump timing): to precisely set pump advance/retard. Required if calibration must be exact (recommended for injection pump work).
- Injection pump puller (specialty tool): some pumps are pressed on or have tight fittings — a puller prevents damage when removing the pump coupling.
- Torque angle/large torque wrench for main mounting bolts: injection pump flange bolts often require higher torque values.
- Professional bench calibration equipment or a shop: injection pumps must be calibrated for fuel delivery and timing; without bench calibration the engine may run poorly, smoke, or be damaged. This is the main reason injection pump replacement often goes to a specialist.

Parts you might need and why
- New lift (transfer) pump assembly and gasket/seal kit: lift pump diaphragms and valves wear; replacement fixes low fuel pressure, hard starting, and starvation.
- New injection pump (remanufactured/OEM) or rebuild kit (rotor, plungers, seals): required if pump is worn, leaking internally, mis‑timed, or seized. Injection pumps require precision; replace or rebuild if suspect.
- Fuel filter and filter element: always replace when changing pumps to prevent contamination and to help bleeding.
- New fuel hoses, clamps and banjo bolt copper washers: old hoses can be brittle; clamps may be corroded and washers crush to seal.
- Gaskets, O‑rings, and mounting bolts (if damaged): ensure leak‑free installation.
- New fuel line fittings or adapters if threads are damaged.

Which pump to attempt as a complete beginner
- Low‑pressure lift pump (easier, recommended for beginners): typically mounted on the side of the block or near the fuel filter. Replacing this is within reach for a basic mechanic with the tools above.
- High‑pressure injection pump (advanced, not recommended for a beginner unless the pump is pre‑timed or prepared by a specialist): requires timing tools, careful marking, and likely bench calibration. If you must replace it, get a reman or rebuilt pump pre‑calibrated and timed by a shop and follow re‑timing steps exactly.

Procedure: lift (transfer) pump replacement (beginner friendly)
- Safety and prep: remove negative battery terminal, put on gloves/eye protection, place drain pan under pump area.
- Locate pump: usually on lower side of engine block near fuel filter or front of engine. Consult a vehicle diagram or the manual to confirm.
- Clean area: use brake cleaner and rags so dirt doesn’t enter fuel system when lines are opened.
- Relieve air in lines: if the system has a manual primer on the filter housing use it to depressurize and remove residual fuel pressure by loosening a bleed screw; otherwise be ready with pan.
- Label fuel lines: tag or photograph each line’s orientation. Take care — fuel line order matters.
- Loosen fuel line fittings: use flare‑nut wrenches on fittings. Turn slowly; catch leaking fuel in the drain pan. Replace crush washers when reassembling.
- Remove electrical connections (if electric pump) or mechanical linkage: use pliers/screwdriver as needed. Mark the orientation of linkage.
- Remove mounting bolts: use the correct socket/wrench. Keep bolts in a clean tray.
- Remove pump and gasket: pry lightly with flat screwdriver if stuck, avoiding gouging flange surfaces.
- Prepare new pump: compare old and new units; transfer any brackets or fittings. Fit new gasket or O‑ring treated with a little clean diesel or oil so it seats.
- Install new pump: place into position, start bolts by hand then use torque wrench to tighten to spec (if unavailable, snug but not overtight — typically 20–40 Nm for small pumps; check manual).
- Reconnect fuel lines with new crush washers and tighten flare nuts with flare‑nut wrench. Reconnect linkage/electrical.
- Prime system: use the hand primer or vacuum priming pump to pull fuel through until fuel flows solidly and no air bubbles appear. Alternatively, crank engine a few seconds at a time (key off between attempts) to prime, but this stresses starter and can suck air.
- Start engine and check for leaks: run at idle, inspect lines and pump for drips. Re‑tighten fittings if necessary.
- Final checks: after 10–15 minutes, re‑inspect for leaks and ensure proper idle and no sputtering. Dispose of used diesel and rags properly.

Procedure: injection pump replacement (advanced; summary and critical steps)
- Understand the scope: injection pumps control timing and fuel quantity; incorrect installation or timing will make the engine run poorly and can damage it. If possible, obtain a remanufactured pump already bench‑calibrated for your engine and set to a known timing position.
- Mandatory tools: timing pin/locking tool, torque wrench, injection pump puller (if needed), dial indicator or degree wheel (for precise timing), and a shop that can bench‑calibrate if you can’t.
- Mark everything: before removal, mark the crank, cam, and pump flange orientation with paint or scribe lines. Photograph multiple angles.
- Lock engine at TDC for cylinder 1 with the service wrench or pin per manual.
- Remove injection pump drive coupling: disconnect fuel lines (use flare wrenches), vacuum/bleed off, remove mounting bolts, and lift pump. Be ready with drain pan.
- Installation of replacement pump: install pump in exactly the same rotational orientation as the old one (use your marks) and loosely fit mounting bolts. Do not fully tighten until timing is checked.
- Rough timing: align pump drive to engine marks, insert pump locking tool. Torque mounting bolts to spec (use service manual values).
- Final timing/calibration: best practice is to bench‑calibrate or have the reman pump pre‑set. If you must set timing on‑engine, use dial indicator/degree wheel and follow the exact factory procedure — this is precise work. If you can’t perform this precisely, get a shop to finish it.
- Bleed fuel system thoroughly: use hand primer or vacuum priming pump.
- Start engine and monitor: look for leaks, listen for unusual noises, check smoke and idle. If rough running persists, stop and re‑check timing and calibration.
- If any doubt about timing, return pump to a specialist for calibration.

Common problems and when to replace parts
- Hard starting, black smoke, loss of power, and fuel leaks: may indicate lift pump failure, clogged filter, or worn injection pump.
- Sputtering, starvation, or engine dies under load: often lift pump or filter problems first — replace lift pump and filter before assuming injection pump.
- External leaks at pump body or failing diaphragms: replace lift pump or gasket kit.
- Erratic fuel delivery, excessive smoke, or poor performance after replacing lift pump: check injection pump calibration — it may need rebuild or bench service.
- Seized pump, broken drive, or heavy internal wear: replace the injection pump with remanufactured unit or send out for overhaul.

Tips and beginner mistakes to avoid
- Never reuse copper crush washers or old gaskets on fuel line unions — they fail to seal.
- Avoid overtightening fittings — you can strip threads or crack castings. Use a torque wrench when possible.
- Don’t allow dirt to enter open fuel lines or pump openings — cap them immediately.
- Label and photograph every hose and fitting so reassembly is exact.
- If you cannot bench‑calibrate or correctly time an injection pump, do not attempt on a hunch — get a remanufactured pump pre‑timed or visit a diesel shop.

What to do if you’re not confident
- Replace lift pump and filters yourself; that fixes many common problems.
- For the injection pump, buy a remanufactured pump from a reputable supplier pre‑set for your engine, or have your pump removed and sent to a diesel shop for bench calibration and return installation instructions. This minimizes the risk of incorrect timing.

Quick parts checklist to buy before starting
- Replacement lift pump or reman injection pump (as required)
- Pump gasket/O‑ring kit
- New fuel filter element
- Copper crush washers for all banjo/union bolts
- Replacement fuel hoses/clamps if aged
- Primer pump or vacuum hand pump (recommended)
- General hand tool set and a flare‑nut wrench set

If you follow the lift pump procedure above you should be able to complete the job with basic tools and the items listed. If you plan to replace the high‑pressure injection pump, treat it as advanced work and secure a pre‑calibrated pump or professional help to avoid engine damage.
rteeqp73

You Might Also Like...

Kryptronic Internet Software Solutions