How to Troubleshoot Diesel Fuel Injectors

Mechanical problems cause headaches and frustration and the last thing you want to find out, is that you could have fixed a problem yourself and avoided the cost of taking it to a mechanic. Diesel fuel injectors are not that much different from gasoline injectors when it comes to troubleshooting even though the actual injection process varies.

  • Test the opening pressure of the fuel injectors. It should fall to 300 psi or less. Anything over this level indicates you should replace the injectors or have them reset to original standards.

  • Assess the nozzle tips on your injectors and see if they need replacing. It's best to spend the extra money and use new nozzle tips as opposed to reconditioned ones since they're not always up to par standards.

  • Watch for black smoke coming from your exhaust. This can be a sign of injectors that are leaking.

  • Check for blue smoke coming from the exhaust as this is a sign of trouble such as low engine compression, scored cylinder walls, worn piston rings or leaking valve stem seals.

  • Take notice of a decrease in power combined with an engine that idols roughly. You may also see white smoke coming out of the exhaust even after the engine has run for awhile and had time to warm up. Dirty injectors can cause these symptoms.