Cleaning Fuel Injector Nozzels
Cleaning injector nozzles should be a part of your normal maintenance program. To get started, disconnect the fuel line from the barrel valve. Next, use your leak down gauge to blow the fuel out of the barrel valve and injector lines. This is also a good time to check where your barrel valve is set. To do this, you will need to also cap off the secondary outlet of the barrel valve with an AN6 cap. This should not change from week to week. If you notice a change in percentage, you need to check to make sure all linkages are tight. Leave injector lines connected during this process. Speedway offers several gauges for this, including; Speedway Dual Gauge Leakdown Tester Tool, Speedway Singe Gauge Leakdown Tester and Longacre Engine Leak Down Tester.
After checking the barrel valve, I will spray WD-40 in the barrel to help lubricate the o-rings in the valve and prevent gumming up. Now you’re ready to use your 7/16 wrench and loosen all the injector lines. Using a 5/8 socket, you can now remove the injectors from the manifold. I use an Ultrasonic Multi-Purpose Parts Cleaner for this process. If you don’t have an ultrasonic cleaner, you can use brake or carb cleaner
Once the nozzles are done in the ultra-sonic cleaner, you need to blow them out with compressed air. Always blow the opposite direction of flow so any debris is blown out of the nozzle and not into it. Hold the nozzle up to a light and look threw it to make sure the nozzle is clean. Repeat this process for all 8 nozzles or all 16 if you're running both up and down nozzles.
After all the nozzles have been cleaned, you can reinstall them. I like to spray a little dab of WD-40 on the o-rings before installing to help keep the o-rings soft and to ensure they seal properly. Do not over tighten nozzles...snug is fine. You can now connect the injector line to the nozzle. Start the lines with your fingers before using a wrench to avoid cross-threading the lines. Once again do not over tighten the lines. Once all lines are tightened, you can reconnect the fuel line to the barrel valve. The job is now complete.