HiAce Van (1KD): No acceleration / lack of power
Suspect the injectors and the supply pump first; they are tied in our cases, and either one failing to deliver fuel properly makes acceleration sluggish. Next: poor contact in wiring and connectors, a soot-clogged DPF, and leaks around the intercooler. On a diesel, 'won't accelerate' means fuel, air or exhaust is short somewhere. The sound when you press the pedal and whether a warning light is on point you in the right direction.
What to suspect, in order
- How to tell (things you can check yourself)
- Listen for idle clatter louder than before. Often paired with hiccups mid-acceleration, white smoke and heavier vibration only when the engine is cold. Note any drop in fuel economy too.
- If you leave it
- Uneven injection keeps combustion unstable and loads the engine and the exhaust filter. Power can drop so far that pulling away becomes difficult.
- Typical repair cost
- Too few cases with a recorded price to give a figure
- How to tell (things you can check yourself)
- Think back: harder starting lately, sudden loss of power on the move? A typical pattern is a sharp drop when you floor it merging onto a motorway or climbing. A check engine light that comes and goes is another clue.
- If you leave it
- It supplies fuel at high pressure; if it weakens, output is unstable and the engine can stop while driving.
- Typical repair cost
- Too few cases with a recorded price to give a figure
- How to tell (things you can check yourself)
- Check for an exhaust or DPF symbol on the dash. With mostly short urban trips, revs rise but the car doesn't go, and the exhaust smells strong. Regeneration happening very often, or not at all lately, is another clue.
- If you leave it
- Power is restricted further and the car may be limited with the light on. Poor exhaust flow also stresses the turbo and other exhaust parts.
- Typical repair cost
- Too few cases with a recorded price to give a figure
- Typical repair cost
- Too few cases with a recorded price to give a figure
- How to tell (things you can check yourself)
- Listen for a hiss or 'pshh' of escaping air when you floor it. Typical pattern: no power only on hills or when loaded, and little sense of turbo boost. Look under the bonnet for a thick hose coming loose at its base or oily seepage.
- If you leave it
- Running short of air makes the mixture rich, producing black smoke and clogging the exhaust filter faster.
- Typical repair cost
- Too few cases with a recorded price to give a figure
This is the order to suspect, nothing more. Diesel power loss often has several overlapping causes. Confirm with an inspection.
FAQ
- It has no power — can I keep driving?
- A short trip to the workshop is usually fine, but avoid motorways and heavy loads. Lacking power when merging or climbing is dangerous. If a light is on or there's smoke or noise, get it seen soon.
- How long does the repair take?
- Cleaning a blockage or fixing wiring is usually quick. Fuel-system parts depend on availability. We give an estimate once the cause is narrowed down.
- Will it pass the inspection in this state?
- Exhaust condition and warning lights affect the test. Heavy black smoke or a lit lamp should be fixed first.
- Will a good motorway run fix it?
- If soot has built up from short trips, sustained driving can help. Once the light is on it often won't recover by itself, and if fuel or wiring is involved, driving changes nothing. Get it checked before a long trip.
Sources
- MLIT Vehicle Defect Information Hotline (Japan)（8 cases）
- Repair shop blogs (Japan)（2 cases）
Created by processing the Vehicle Defect Information Hotline data (Ministry of Land, Infrastructure, Transport and Tourism, Japan) (https://renrakuda.mlit.go.jp/renrakuda/opn.html)
No text is quoted from these sources. Only the facts of each case (model, symptom, cause, cost) are aggregated.
Reviewed by Tama Inc. (workshop certified by the Kanto District Transport Bureau) Reviewed on 2026-09-11 Updated 2026-09-11
This page shows what to suspect first, based on aggregated nationwide repair cases and our own experience. Always confirm the cause with an inspection. Repair costs are medians and ranges from the cases; they vary by vehicle condition, region and workshop.
For lack of power, look at soot on the intake side (EGR and intake manifold) before replacing parts. Many come back to life after a clean. Check fuel pressure and injector correction values on the scan tool at the same time.