Precision Engine Performance
We specialize in professional remanufacturing of diesel fuel injectors, high-pressure fuel pumps, and BMW xDrive transfer cases. Advanced diagnostics, fast UK & EU shipping, and trusted warranty.
Brake Cleaner 5L
Professional brake & fuel-system cleaner — removes grease, oil and dust.
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Full parts catalogue
Reman parts, repair kits and chemicals — ready to ship.
Browse the shop →Reman alternators
Rebuilt & bench-tested under load — brushes, regulator, rectifier, bearings.
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Reman starter motors
Rebuilt & bench-tested under load — solenoid, brushes, bendix, bearings.
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Our Specialized Services
Select a division to learn more, view pricing, or request a quote
Diesel Fuel Injectors
Remanufacturing, testing and coding for Bosch, Delphi, Denso and Continental injectors.
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High-Pressure Pumps
Testing, cleaning and rebuilding of diesel high-pressure pumps.
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Advanced Injector Testing
Precise diagnostics on test benches — full flow & spray reports.
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BMW xDrive Transfer Cases
Top Transfer Box — repairs, gear and clutch-pack service for xDrive.
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Remanufacturing of starter systems for cars and vans.
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Charging-system rebuilds with a full load test.
Check it →How it works
Four steps to a healthy fuel system
Diagnosis
We receive the unit and run an initial fault diagnosis.
Remanufacturing
Cleaning, replacement of worn parts and calibration.
Bench test
Flow and leak-tightness measured — full report.
24h dispatch
We send the finished unit back with a 12-month warranty.
Refundable Core Deposit
How Our Deposit System Works
Buy Your Part
Order online — pay the item price plus a refundable core deposit.
We Dispatch Fast
Your reconditioned part ships out, usually within 24h.
Return Your Old Core
Post your old, faulty unit back to us in the same packaging.
Deposit Refunded
Once we verify the core, your deposit is refunded to your original payment method.
Please Check Before Returning
What Disqualifies Your Old Core From a Refund
Strong Corrosion
Heavily rusted or corroded housings and connectors cannot be accepted for a deposit refund.
Disassembled Units
Cores that have been taken apart or are missing original components are not eligible.
Mechanical Damage
Cracked, bent, or physically broken housings will be declined.
Got faulty injectors or a pump?
Send it for a free quote — usually the same day.
Why Choose Top Injectors?
Advanced Diagnostics
We use OE-level Hartridge and Bosch test benches to ensure microscopic precision.
12-Month Warranty
All rebuilt injectors, pumps, and transfer cases are covered by a full 1-year warranty.
Fast Shipping
Next-day delivery available within the UK. Fast and secure international shipping across EU.
Technician Support
Direct communication with our team of specialists for diagnostic advice and technical support.
Customer Feedback from eBay
Real reviews from our official eBay store
"Fast delivery, injector works perfectly, coding was accepted immediately. Highly recommended! 5*"
"Excellent service! Sent my BMW injectors for testing, got reports next day and they repaired the faulty one. Saved me a lot of money."
"Very professional company. Rebuilt my xDrive transfer case and now the car drives like new. No more shuttering. Thank you!"
"Top quality Brake Cleaner, cheap price for 20L and fast shipping. Will buy again."
Diesel Fuel Injector Remanufacturing
At Top Injectors, we provide comprehensive remanufacturing services for all major diesel injector brands, including Bosch, Delphi, Denso, and Continental/Siemens.
Our process includes complete disassembly, ultrasonic cleaning, inspection of all internal components under microscope, replacement of worn parts (nozzles, control valves, seals) with high-quality components, and final calibration on advanced test benches.
- Full diagnostic report showing flow rates, backleak, and response times
- New IMA / C2i / C3i codes generated where applicable
- Remanufactured to strict OE standards
- Exchange basis or repair of your own units
- We offer both remanufactured injectors and used (second-hand) injectors with test confirmation
High-Pressure Diesel Pump Services
We offer testing and full rebuild services for high-pressure diesel injection pumps, including Bosch CP1, CP3, CP4, Delphi DFP, Denso HP, and Siemens/Continental PCR.
A faulty high-pressure pump can produce metal shavings that contaminate the entire fuel system. We thoroughly clean, rebuild, and test every unit to guarantee reliable pressure generation and prevent future engine damage.
- Complete pressure and flow rate testing across all RPM ranges
- Replacement of internal seals, transfer pumps, and pressure regulators
- Thorough decontamination and clean-room assembly
- Calibrated to manufacturer specifications
Advanced Injector Diagnostics
Not sure if your injectors are faulty? Before committing to a full rebuild, send them to us for professional testing. We use the latest diagnostic benches to run a full sequence of tests.
Testing includes resistance checks, nozzle opening pressure, spray pattern visualization, idle/mid/full load delivery rates, and backleak measurement.
- Detailed PDF report for every tested injector
- Quick turnaround - usually within 24-48 hours
- Affordable diagnostic rates (credited if we rebuild them)
- Helps pinpoint engine misfires and smoke issues
BMW xDrive Transfer Cases
Welcome to Top Transfer Box, our specialized division dedicated to the diagnosis, repair, and strengthening of BMW xDrive transfer cases. We handle models such as ATC35L, ATC45L, ATC300, ATC350, ATC400, ATC450, ATC500, ATC700, and more.
Common symptoms of a failing transfer case include jerking/stuttering under acceleration, clicking noises under the car, or dashboard warning lights (4x4, ABS, Brake). We rebuild transfer boxes with reinforced internals to prevent future failures.
- Replacement of worn clutches with high-performance friction plates
- New upgraded actuator gears and heavy-duty bearings
- Complete unit testing and pre-filled with high-grade xDrive fluid
- 12-month warranty on all rebuilt units
No Public Retail Prices - Custom Quote Only
Due to the variety of BMW xDrive models, gear ratios, and specific rebuild requirements, we do not publish flat retail prices. We provide customized, competitive quotes based on your vehicle's VIN or Registration Number.
Top Transfer Box - Specialized repairs, gear replacement, and clutch pack service for BMW xDrive systems.
Starter Motor Repair & Reconditioning
At Top Injectors, we diagnose, repair, and fully recondition starter motors for diesel and petrol vehicles, vans, and light commercial fleets. Every unit is stripped, inspected, and rebuilt in our Coventry workshop — then proven on our own dedicated starter and alternator test bench.
Common symptoms of a failing starter motor include a clicking noise on ignition, slow or no cranking, intermittent starting, or a grinding sound when the engine turns over. We test each starter under load both before and after the rebuild to confirm reliable performance.
- Replacement of worn brushes, solenoids, and bendix/drive gears
- Bearing and bushing replacement where required
- Full bench test under load before dispatch
- 12-month warranty on all reconditioned units
No Public Retail Prices - Custom Quote Only
Because starter motors vary widely by make, model, and engine size, we don't publish flat retail prices. Send us your vehicle's registration or the starter motor's part number for a fast, competitive quote.
Top Starters - Diagnosis, repair, and reconditioning of starter motors, with a 12-month warranty on every unit.
Our own test bench
Every starter and alternator is load-tested on our in-house bench — before and after reconditioning.
Alternator Repair & Reconditioning
Top Injectors also handles the diagnosis, repair, and full reconditioning of alternators for diesel and petrol vehicles, vans, and light commercial fleets, right here in our Coventry workshop.
Common symptoms of a failing alternator include a dashboard battery warning light, dimming or flickering headlights, a flat or under-charging battery, or a whining noise from the engine bay. Every alternator is load-tested on our own dedicated alternator and starter test bench — both before and after reconditioning — to confirm correct charging output.
- Replacement of worn brushes, bearings, and diode packs
- Voltage regulator testing and replacement where required
- Full bench test under load before dispatch
- 12-month warranty on all reconditioned units
No Public Retail Prices - Custom Quote Only
Because alternators vary widely by make, model, and amperage rating, we don't publish flat retail prices. Send us your vehicle's registration or the alternator's part number for a fast, competitive quote.
Top Alternators - Diagnosis, repair, and reconditioning of alternators, with a 12-month warranty on every unit.
Our own test bench
Every starter and alternator is load-tested on our in-house bench — before and after reconditioning.
Premium Workshop Chemicals
Featured Product: Premium Brake Cleaner
Our high-pressure, fast-evaporating Brake Cleaner quickly removes brake dust, grease, oil, and grime from brake discs, pads, drums, and clutch components. Leaves no residue.
Order Brake Cleaner
How to Order Chemicals
To purchase our workshop chemicals, contact us directly via phone, email, or WhatsApp. We offer local collection in Coventry and fast shipping options.
Chemicals
Premium cleaning and maintenance fluids. Promoted offer: High-performance Brake Cleaner.
Official Online Shop
Contact & Location
Get in touch with our team for advice, bookings, or price quotes
Address
Unit 5 Rowley’s Green Ln, Longford, Coventry CV6 6AN
Phone & WhatsApp
Opening Hours
Monday - Friday: 9:30 AM - 4:30 PM
Saturday: 9:00 AM - 2:00 PM
Sunday: Closed