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DIESEL INJECTION SPECIALISTS

EUI Injector Specialists – Precision Testing & Calibration in Auckland

Restore engine performance with professional Electronic Unit Injector diagnostics, testing, rebuilds and calibration. Simms Diesel services trucks, heavy equipment, marine and industrial engines with fast turnaround and expert workmanship.

Book A Repair

Call 09 579 1159
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Request a EUI Injector Quote

✅ Typical response time: Same business day.

Established Diesel Injection Experts

Trusted EUI and diesel injection specialists servicing Auckland and Northland for decades.

Advanced EUI Calibration & Testing

Specialist bench testing and precision calibration equipment ensures every injector is rebuilt and set to exact manufacturer specifications.

Fleet & Commercial Injection Support

We understand downtime costs money. Our structured injector repair process keeps your trucks, plant and machinery running reliably.

Quality Parts & Verified Performance

We use quality components and verify every EUI injector through comprehensive testing before it leaves our workshop.

COMMON EUI INJECTOR SYMPTOMS

Losing Power?
Excess Smoke or Rough Idle?

Electronic Unit Injector (EUI) faults can cause hard starting, power loss and inconsistent performance under load. Because EUI systems control fuel delivery electronically and mechanically, accurate bench testing is essential before replacing parts.

If you’re experiencing any of the following, your injectors may need professional inspection:

Common signs your EUI injectors may require testing:

Hard start / no start (even with good fuel supply)

Loss of power or poor throttle response

Excess black or white smoke under load

Rough idle, misfiring or surging

Increased fuel consumption

Fault codes relating to injector performance

HOW IT WORKS

Our EUI Injector Service Process

We follow a structured EUI testing and rebuild workflow to ensure accurate diagnosis, reliable repairs and consistent performance — without unnecessary part replacement.

1

Inspect & Bench Test

We perform electronic and mechanical testing to confirm injector faults before any repair work begins. Accurate diagnosis prevents unnecessary replacement costs.

2

Strip, Rebuild & Component Replacement

Injectors are carefully dismantled, internal components inspected, and worn parts replaced using quality components matched to manufacturer specifications.

3

Precision Calibration & Verification

Each EUI injector is calibrated and validated on specialised test equipment to ensure correct fuel delivery, timing and performance before leaving our workshop.

Request A Quote

Call Workshop

COVERAGE

What We Service

Built for diesel across industries — if it runs on diesel, we can likely help.

Heavy Transport & Fleet

EUI injector diagnostics, rebuilds and calibration for heavy trucks and commercial fleet vehicles.

Construction, Industrial & Plant

Precision injector repair for excavators, loaders, generators and high-load diesel applications.

Agricultural & Selected Marine Applications

Electronic injector servicing for tractors, harvesters and selected marine diesel platforms.

CUSTOMER REVIEW

Trusted by Fleet Operators Across Auckland

“Accurate injector testing and calibration. Clear communication and no unnecessary part replacement. Highly recommend Simms Diesel for EUI work.”

Charles S. – Fleet Manager, Transport Company, Auckland
Thanks for contacting us. We'll get back to you as soon as possible.

Request an EUI Injector Assessment

Tell us your engine details, injector type and symptoms — we’ll recommend the most cost-effective solution based on proper testing and diagnosis.

✅ Typical response time: Same business day.

✔ No-obligation assessment

✔ Experienced EUI Injector Techs

✔ Auckland workshop support

FAQ

EUI Injector Service – What You Need to Know

Clear answers to common questions about EUI injector testing, rebuilds, exchange options and workshop turnaround.

How long does EUI injector repair take?

Turnaround time depends on injector type and parts availability. In most cases, testing and rebuild work is completed within a few business days. We provide a clear timeframe once bench testing confirms the fault.

Do you test injectors before repairing them?

Yes. Every EUI injector is electronically and mechanically bench tested before any repair work begins. Accurate diagnosis ensures only necessary components are replaced and prevents unnecessary costs.

Can I courier my injectors to you?

Yes. We accept injectors from workshops and fleet operators across New Zealand. Secure packaging is important to prevent damage in transit — contact us for shipping guidance.

Do you offer exchange injector options?

Where available, we can supply remanufactured or exchange EUI injectors to minimise downtime. Availability depends on engine platform and stock levels.

What brands of EUI injectors do you service?

We service a wide range of diesel injection brands including Bosch, Cummins, CAT, Detroit, Volvo, Scania, Perkins, Delphi, Denso, Stanadyne and more. If you’re unsure, contact us with your engine details.

What are common signs of EUI injector failure?

Common symptoms include:
• Hard starting
• Loss of power
• Excess smoke under load
• Rough idle or misfiring
• Increased fuel consumption
• Fault codes related to injector performance

Our Services

Comprehensive diesel system repair and testing — all handled in-house by experienced specialists.

PUMP REPAIR

CAT REPAIR

TURBO REPAIR

DIAGNOSIS

DPF CLEANING

INJECTOR REPAIR