Teledyne Continuous Flow Fuel Injection

Repair Stations Threatened Part 145 recommendations may shut you By Stephen P. Prentice March 2000 Stephen P. Prentice is an attorney whose practice involves FAA-NTSB issues. He has an Airframe and Powerplant certificate and is an...


Before beginning the fuel injection setup procedure, be sure to have appropriate aircraft and engine manuals to accomplish the procedure. Begin with the aircraft manufacturer's instructions and if they don't provide any data for adjusting the fuel injection system, refer to the appropriate Continental engine manual. Also, aircraft and engines that have been modified from their original type design must be maintained in accordance with the STC holders FAA- approved instructions.M

Make a copy of the Operational Test Form from TCM Service Information Directive SID-97-3. Record Idle and full RPM, metered and unmetered fuel pressure, fuel flow, manifold pressure, and idle mixture rise.

Pre-Setup requirements
First, verify the accuracy of the aircraft engine instruments, tachometer, manifold pressure gauge and fuel flow gage must be verified. For safety's sake, perform all work and make all adjustments with the engine stopped and the ignition and master switches in the OFF position.

Remove, inspect, and clean fuel system screens and filters in according to aircraft manufacturer's instructions. There are two instances where the fuel system must be flushed prior to continuing: 1) At engine installation, and 2) whenever fuel system components are replaced.

To flush the aircraft fuel lines in the event of an engine change, attach a length of hose to the fuel pump inlet hose and run the boost pump long enough to allow a minimum of one gallon of fuel to flow into a clean container. Inspect the fuel for contamination and continue to flush if any contamination is noted. If components in the fuel injection system are changed, associated fuel injection system lines must be flushed as well.

Next, verify proper routing and attachment of fuel injection system plumbing, verify proper installation of fuel pump vapor return line and check valve. Inspect the induction air filter for cleanliness and proper operation. Ensure proper operation of the alternate air source. Verify the throttle and mixture control and propeller control linkage operate properly, are rigged correctly, are lubricated, and are in good condition. Inspect the induction, exhaust, and fuel injection system for leaks, stains, chafing of lines, etc., and correct any problems before proceeding.

Connecting test equipment
Keep in mind that hose diameters on your test equipment can impact the readings you get while adjusting the fuel system. That's why it's important to be sure all fittings, T-connectors, and hoses are at least the same inside diameter as the pump outlet fitting. Extra length test hoses can also adversely affect the results. Following the aircraft manufacturers instructions, turn the fuel selector valve to the off position.

Loosen and remove the unmetered fuel supply hose from either the fuel pump outlet fitting or the fuel control inlet fitting, whichever is more accessible. Some aircraft have an unmetered fuel pressure fitting you can access at the fuel control screen.

Attach the unmetered fuel supply hose to the straight end of the T-connector and torque, then install and torque the swivel-T directly to the fuel pump outlet fitting or fuel control inlet fitting as applicable. Then, connect the line to the portatest unit or test gages. Be sure test hoses are sufficient length to be out of the way for engine runup.

Next, install the second swivel-T to measure metered fuel pressure. To accomplish this, disconnect the fuel inlet to the manifold valve fuel inlet fitting and iT-fitting. Then connect the portatest unit to the swivel-T. Torque as specified in TCM Service Information Directive SID-97-3 or most current revision.

Using the aircraft boost pump, pressurize the fuel system to bleed all air from the lines and hoses and check for leaks. Correct any problems before continuing. Also, be sure to allow sufficient time for fuel to drain from the entire induction system prior to starting the engine. Failure to comply could result in a hydraulic lock event.

Next, locate the idle speed stop screw on the throttle body and back it out two complete turns. During setup, idle speed rpm will be adjusted manually using the cockpit throttle control.

Before reinstalling the cowling, position test hoses so they are away from the exhaust system and are not damaged.

Performing the setup

With the test equipment connected, it's time to perform the setup.

Obtain the appropriate data for setup from the appropriate manuals.

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