Fuel Injector test data sheet explanation
We try to include the necessary amount of test data to insure that the injector is operating correctly. More data points typically isn't of any use to most customers.
Note: Some shops boast about "Color Test Reports", but WitchHunter Performance has determined through careful testing that fuel injectors work just as well with any color ink used in printing the test reports.
The information in gray areas indicate the before cleaning data. The after cleaning data are in the white areas.
If you see a zero in the before cleaning data, it means the the injector was stuck shut. We consider an injector stuck if it doesn't start working during the first 60 seconds.
Fluid Temp - The temperature of the test fluid during testing. It is very important to keep the test fluid temperature stable to insure valid results. Very few shops control their test fluid temperatures. We design our own temp controllers and even layout the circuit boards for them.
Test Machine # - Just an indication of what flow test machine was used for quality control purposes. More than one machine can be used due to before and after testing.
Test Pressure - Most tests are performed at 43.5 psi (3 bar), the standard for injectors. TBI and CIS are tested at a different pressure. Customers may specify a different value.
Resistance - The coil resistance at room temperature. Normally the readings should be within 10% of each other.
Leak Test - The injectors are checked for leaks at 10, 40, and 100 psi. This test is performed 3 times before cleaning and 3 times after cleaning since small leaks are difficult to detect.
Spray pattern - A visual check of how the injector atomizes the fluid while it's operated. This can be good, fair, or poor. An X is put in the box if the injectors wasn't working at all during the test.
Static Flow - The injector is held open for and the volume is measured in cc's.
Pulsed Flow - The injector is pulsed on and off to simulate normal operation and is a very good indicator of how well the injector is working. This tests the internal spring condition as well as how clean they are.
The absolute value is not important, the thing to look for here, is how close they are to one another. The graph on the bottom of the test sheet is generated from this data.
CC/Min - This value is generated from the static flow data above and indicates the flow of the injector at the indicated test pressure.
Static Variance - This is the difference in percent between the lowest and highest flowing injectors from the static flow test numbers above. A low number is good and will normally be less than 5%. Both before and after servicing values are included.
Pulsed Variance - This is the difference in percent between the lowest and highest flowing injectors from the pulsed flow test numbers above. A low number is good and will normally be less than 5%. Both before and after servicing values are included.
Graph - This graph in generated from the pulsed flow test for ease of interpretation.