A20DTJ Injector Problems – Symptoms, Causes & Fixes

Engine: A20DTJ 1 compatible injectors From £80

Common Injector Failures on the A20DTJ

The A20DTJ engine uses high-pressure common rail diesel injection. Over time, injector nozzles wear, seals degrade, and internal components lose calibration. This leads to a range of drivability symptoms that worsen if left unaddressed. We stock 1 tested replacement injectors for this engine from Bosch.

Vehicles fitted with the A20DTJ include models from Vauxhall. If you are experiencing any of the symptoms below, your injectors may need testing or replacement.

Symptoms of Injector Failure

Related Fault Codes

P0201 P0202 P0203 P0204 P0263 P0266 P0269 P0087 P0089 P0300

How to Test A20DTJ Injectors

Leak-off test: Connect clear hoses to the injector return lines and compare fuel volumes at idle. The injector returning the most fuel is likely worn.

Correction values: Use a scan tool to read injector correction (IMA) values. Readings beyond ±3 mg/stroke indicate wear.

Resistance check: Measure resistance across the injector connector pins with a multimeter. Compare to manufacturer specs.

Complete Testing Guide Leak-Off Test Guide

A20DTJ Injector Replacement Cost

Parts (per injector)

£80–£80

Labour

£150–£400

Total (per injector)

£230–£480

Full replacement cost guide

Compatible Injectors for the A20DTJ1 found

0445110423Bosch

£80.00

Related Cross Reference Numbers for A20DTJ

0445110393 0986435237 55564969

Related Engine Codes

A20DTE

Frequently Asked Questions

What are common injector problems on the A20DTJ engine?

The A20DTJ engine commonly suffers from injector seal failure, nozzle wear causing poor spray patterns, and back-leak issues. Symptoms include rough idle, black or white exhaust smoke, hard starting, and increased fuel consumption. These issues typically appear after 100,000–150,000 miles.

How much does it cost to replace injectors on a A20DTJ engine?

A remanufactured injector for the A20DTJ engine typically costs £80–£80 per injector. Labour adds £150–£400 depending on accessibility. We found 1 compatible injectors for this engine.

Which vehicles use the A20DTJ engine?

The A20DTJ engine is found in vehicles from Vauxhall. Common models include Vauxhall Astra J, Vauxhall Insignia, Vauxhall Zafira Tourer.

How do I test the injectors on a A20DTJ engine?

Perform a leak-off test by connecting clear hoses to each injector return line and comparing fuel volumes at idle. You can also check injector correction values with a diagnostic scan tool or measure electrical resistance with a multimeter.

Injector Compatibility Checker

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Need a Replacement A20DTJ Injector?

We stock 1 tested replacement injectors for the A20DTJ engine. All remanufactured, bench-tested, and supplied with a 12-month warranty.

View All Injectors Replacement Cost Guide Call 020 3355 6581