Case Studies

Fuel Injector End-of-Line Test System

Posted in LabVIEW, Test & Measurement Automation


DMC developed software to conduct automated signature analysis and quality control of fuel injectors for production line testing. The system is a replacement of older, less feature-rich software used to test the operation of each injector.

AVL Fuel Balance

AVL Fuel Balance

NI cDAQ-9188

NI cDAQ-9188


The new DMC application conducts a more thorough characterization, databases each test for later lookup by customers, and is fully automated. It also has several features that allow the client’s engineering staff to collect high-speed data of the injector’s electrical signals. The client has in-depth knowledge of their fuel injectors, but is short on time and programming resources to develop the software. Previous successful projects with this client brought them back to DMC to develop this application.

DMC delivered an automated system for testing fuel injectors as they exit the production line. The tests are used to characterize the injector’s quality, as well as to tag each injector with values that are used to synchronize it with the engine’s electronics. Previous test procedures falsely failed more injectors than necessary, so DMC collaborated closely with the client in order to implement novel signal analysis techniques intended to produce more accurate results. The test results are logged to a database that allows sharing data both with the client’s other production steps and with the end-user. Each test, regardless of how it is configured, is completely automated from start to finish. This means that a single operator can man several test stations at once with very little supervision, permitting time for him or her to focus on other quality control tasks in the production line.

The solution involved multiple hardware and software components, all of which communicate with the main LabVIEW application. High-speed analog data is collected with the CompactDAQ system. The client’s existing Measurement Computing hardware was retained, and handles all digital I/O. A fuel balance from AVL provides precise measurements of consumed fuel and communicates via RS232. The application logs results from the tests in the client’s MySQL database, which is queried in subsequent production line steps, and is available to end-users.

Learn more about DMC's LabVIEW programming services.

Customer Benefits

  • Very flexible test sequences and parameters can be used on multiple injector types
  • Clean, familiar interface allows the client to easily transition from the old to the new software
  • Built-in pressure and temperature monitoring keeps operators and equipment safe
  • Sophisticated algorithms characterize each injector more accurately than previous applications, reducing false rejections
  • Updated hardware collects data at very high sample rates, permitting analysis of important and previously unused signals


  • National Instruments LabVIEW
  • National Instruments USB Compact DAQ (cDAQ)
  • Measurement Computing PCIM-DAS1602/16 DAQ card
  • AVL Fuel Balance
  • Barcode Scanner
  • Microsoft Windows 7
  • Oracle MySQL