MANUTEX TU-443 Fuel Pressure Test Kit Fuel Pressure Gauge Complete Kit Instruction Manual

MANUTEX TU-443 Fuel Pressure Test Kit Fuel Pressure Gauge Complete Kit

To the best of our knowledge, the information in this book is correct.As the information has to be general to cover all makes and models world-wide, there may be a limited number of care of models that may vary from the general instructions, lf in doubt, consult factory, Bosch, Mitchell,or other manuals for more specific information.

PRESSURE CONVERSION CHART

METRIC CONVERSION CHART

Pretest System Checks

The following basic checks should be performed and any detected faults corrected before a fuel system test is performed.

Fuel system

• A. Look for broken or loose fuel lines (metal or rubber)
• B. Make sure fuel tank has sufficient fuel (do not rely on fuel gauge).
• C. Check for water or other contaminants in fuel.
• D. Check condition of fuel system related fuses.
• E. Check condition of fuel tank venting systems.
• F. Check condition of fuel tank filler cap.

Electrical System

• A. If engine won’t start, check for ignition spark using a testPlug.If no spark, repair ignition system. The ignition fires the injector on most fuel injection systems so that if there is no spark plug firing, there will be no injector firing.
• B. Obeserve check engine lamps or other computer fault indicators.
• C. Look for ignition wires broken,disconnected or arcing.
• D. Look for distributor cap or rotor disconnected or arcing.
• E. Check for component grounds loose or corroded.
• F. Look for disconnected electrical components.

Battery &Charging System

• A. Check battery condition A weak battery will not ensure proper pump delivery or injector triggering. Should be over 12 volts.
• B. Check basic operation of charging system
• C. Look for loose or corroded battery calbes.

Miscellaneous

• A. Check vacuum lines for loose or disconnected lines.
• B. Look for water leaks.
• C. Look for excessive oil leaks.
• D. Listen forany audible air leaks, unusual noises, fuel pump buzz(a noisy pump may not be an indication of poor operating condition), engine rattles or knocks.
• E. Check valve timing and adjustment.

PARTS & ASSEMBLIES FOR FUEL INJECTION

TROUBLE SHOOTING MULTI-PORT& TBI SYSTEMS

FUEL PRESSURE DIAGNOSIS

Fuel Pressure problems generally fall into two categories:higher than normal and lower than normal operating pressures. The fuel supply system is a closed loop system.Fuel is prmped from the tank to the pressure regulator and injectors.and excess fuel is returned to the tank.The fuel pressure regulator is the dividing point between the supply side and the return side.A higher than normal pressure is generally caused by a malfunction in the return side, and a lower than normal pressure is generally caused by a problem in the supply side.

Higher than normal pressures can usually be attributed to faults such as:

• defective fuel pressure regulator
• restriction(bend or kink)in return line
• flexible coupling at tank
• excessive tank pressure caused by a poor vent system

Lower than normal pressures can usually be attrbuted to faults such as:

• clogged fuel filter
• restriction (bend or kink) in supply line
• defective fuel pump
• defective pressure regulator
• flexible coupling at tank
• clogged fuel filter sock in tank
• low pressure in tank(vacuum)caused by improper venting

Restrictions are usually coupled with a low flow rate where as a detectve pump or pressure regulator could maintain proper flow rate but not pressure.

If any of these conditions exist, component isolation is generally the fastest route of diagnosis(example:whenever possible,disconnect lines before and after component or line.check pressure and flow before and after component or line

If the pressure is too low, test the fuel pump volume, Also,there may be a blockage in the supply line or leakage in the return line.
If the system has none of these, the fuel system pressure needs adjustment. Consult the factory manual or fuel injection manual for the procedure.

• If Rest Pressure drops too quickly, check for leaks at O’rings and fuel line connections.If no external leaks, check for a leaking cold start valve of fuel injectors. If still no leaks there, leakage may be at the fuel pump check valve of at the O’ring.on the relief valve in the fuel distributor. Repair of replace.

• If no problems can be found in the fuel injection system through pressure testing, fuel pump should be checked.For this, your tester should have a bleed-off valve and tubing. If you do not have one,it can be purchased trom your tool supplier, With gauge hooked up to pressure test, put a bleed-off tube into a fuel container of at least 2 quarts of 2 liters, Fuel flow in 30 seconds should be 1.5-2.0 pints or 3/4-1 liter. Turbo cars may have a volume of 20-25%more than non-turbo.

• Deactivate ruel pump and relieve tuel system pressure, With key off, put bleed-off tubing in a fuel can and press bleed-off valve.
  If your tester has no bleed-off valve assembly, wrap rags around connections and release slowly. A bleed-off assembly can be purchased from your tool man.

• Remove tester and reconnect all lines.

• Start engine and check for leaks.

• Remove fuel from all hoses. If fuel remains in gauge hose assembly,connect the smallest banjo bolt adapter into the quick coupler over a fuel container. Hold gauge above hose and fuel will flow into the fuel can.

TYPICAL C.I.S.
PRESSURE TESTING FUEL INJECTION HOOKUP

ADDITIONAL INSTRUCTIONS FOR TESTING BOSCH CIS

Four pressure teste can be made with this tester:

• Cold Control Pressure-engine cold, valve open
• Warm Control Pressure- engine warm, valve open
• Primary Pressure-engine cold or warm, valve closed (closed) valve eliminates control presure)
• Rest Pressure-engine warm,valve open

The CIS pressures shown in this book ard for the warm control pressures. For pressures for teste A&C, consult the vehicle service manual, a Mitche | Fuel Injection manual, or Robert Bosch Service Guide booklet for Fuel Injection.

To make tests:

1. For lest “A” (above), the engine should be cold, standing several hours or overnight.

2. Relieve fuel system pressure (see pp. 10-11).

3. Make sure fuel filter is not cilgged. Replace if doubtful.

4. Clean dirt off the fuel distributor top.

5. Referring to the typical CIS hookup diagram, hook up the tester between the fuel distributor and the controi pressure regulator.
   The hose without the flow control vaive should be connected to the center of the fuel distributor. The hose with the valve should be connected to the hose removed from the fuel distributor of connecte directly to the control pressure regulator.

   • CAUTION: hand tighten any adapters withO rings to avoid damage to O’ rings.
   • In a few cases, to get the right combination of threads to connect, the adapters may have to be piggy-backed.

TYPICAL FUEL INJECTION PRESSURE TEST

(For Bosch CIS & GM TBI,see additional instructions)

All pressure tests should be made at idle on the high pressure side of the system.

1. With engine off .locate fuel pressure port (Schrader Valve)and attach ruel pressure gauge, If no Schrader Valve is provided and system must be opened, residual pressure must be released before fittings are loosened to keep gasoline from spraying all over,possibly causing eye injury or a fire, See our “Fuel Pressure Release”chart on pages 10-11 and follow instructions.Connect tester using the correct adapter and access point. Always wrap a shop towel around fitting before loosening.

2. If the adapter you use is a banjo bolt adapter, ours is designed to use with standard banjos. If a car manufacturer uses a nonstandard banjo, more than one washer may be needed on either or both sides of the banjo. Our M12x1 25 banjo bolt adapter may need one or more thick or thin washers depending on the application.

3. With gauge connected or teed into system using proper adapters,reactivate fuel pump,start the engine and check for leaks.If no leaks are detected, observe gauge. Pressure should rise to slightly above operating pressure and then stabilize at operating pressure (as per manufacturer’s specifications). See our” Adapter Application and Specification” chart on page 12.

4. Start engine. If an adjustable fuel pressure regulator is used,pressure should be maintained during running. If a compensating fuel pressure regulator is used, pressure should drop approximately 8-9 PSI, depending on maniflid vacuum.

5. Observe rapid increase in dead-end pressure.
   CAUTION: Pressure could exceed 75 PSI and may blow any loose fittings or defective lines. Observe condition of system before this test.

6. If pressures are acceptabe, some manufacturers also require a flow test, lf so, at this point open the fuel system into a graduated plastic container and observe flow rate (example: one pint/15 seconds) Close system.
   Turn key off and observe residual pressure. Some manufacturers prescribe a minimum holding time.

7. In conjunction with an injector pulse tester, turn key on, observe pressure,pulse one injector, observe pressure drop, turn keyoff, move tester to next injector, turn key on, observe pressure,pulse injector, observe drop, turn key off, continue with remaining injectors.
   CAUTION:Do not repeat this test more than manufacture’s recommendations. Flooding of engine may occur.

8. Deactivate fuel pump and relieve ruel system if necessary. With key off, put bleed-off tubing in a fuel can and press bleed-off valve. If your tester has no bleed-off valve assembly, wrap rags around connections and release slowly, A bleed-off assembly can be purchased from your tool man.

9. Remove tester and reconnect all lines.

10. Start engine and check for leaks.

GM TBI ADAPTER APPLICATIONS CHART K

ADDITIONAL INSTRUCTIONS FOR TESTING GM TBI

1. Relieve fuel system pressure (see pp. 10 – 11).

2. Remove the air cleaner assembly.

3. Temporarily plug the Thermac vacuum port on the throttle body.

4. Refer to our GM TBLAdapter Chart below,and using the adapters we supply, install the tester in line between the fuel filter and throttle body. If longer pieces of ⅜” hose are needed cut from ⅜* fuel line. Use hose clamps on hose.

5. If steel tubing is removed, use two wrenches to prevent damage.

6. On some cars, it is easier to put the car on a lift and test trom underneath.

7. Onsome cars with GM TBI systems, it is hard to install adapters, With the adapters and tubing furnished, many combinatons can be made to help you.

8. Reactivate fuel pump, start the engine and check for leaks.

9. When fuel pressure has stabilized after a minute or so, gauge should read 9 – 13 PSI (62 – 90 kPa), (.6 -.9 bar) and (.63-91 Kg/cm’).

10. Deactivate fuel pump, and relieve fuel system pressure. With key off, put bleed-off tubing in a fuel can and press bleed-off valve. if your tester has no bleed-off valve assembly, wrap rags around connections and release slowly. A bleed-off assemboy can be purchased from your tool man.

11. Remove tester and reconnect all lines.

12. Start engine and check for leaks.

13. Remove fuel from all hoses. If fuel remains in gauge hose assembly, connect the smallest banjo bolt abapter into the quick coupler over a fuel container. Hold gauge above hose and fuel will flow into the fuel can.

14. Remove the plug from the Thermac and replace air cleaner.

15. Locate a flexible hose on the return side and gently squeeze off return flow briefly, Never squeeze a steel braided hose.
    CAUTION: Some pump designs can be damged by this test and test should not be performed unless recommended by manufacturer.

16. Remove fuol from all hoses.If fuel remains in gauge hose assembly,connect the smallest banjo bolt adapter into the quick coupler over a fuel container Hold gauge above hose and fuel will flow into the fuel can.

TYPICAL MULTI-PORT FUEL INJECTION SYSTEM WITH SCHRADER VALVE

PROCEDURE TO RELIEVE FUEL SYSTEM PRESSURE

1. Do not smoke.
2. Wear a pair of safety glasses.
3. Keep a dry chemical(Class B) fire extinguisher near you.
4. Releasegas cap with ignition off.
5. Disable fuel pump as per our Fuel Pressure Chart below.
6. On some vehicles, a satisfactory method of disabling the fuel pump(s) is to remove the fuel pump fuse(s). But on other vehicles, removing the fuse(s) disables the fuel injectors or ignition system,so another disabling method must be used. Refer to our chart below.
7. Some vehicles not specifically mentioned in our Fuel pressure Release chart may have two fuel pumps.Make sure both are disabled
8. Tum the ignition key on and start the engine.
9. Run the engine until it stalls.
10. Try to restart the engine for 3-5 seconds. For cars with inertia switch pressure relief, engage starter 15 seconds to relieve fuel pressure.
11. Tum ignition key off.

• A – Fuel Line to (Fuel)Rail
• B — Fuel Line to TBL
• C – Fuel Rail – Standard Schrader Flex Adapter
• D – Fuel Rail – Small Schrader Flex Adapter (Ford)
• E – Fuel Rail
• F – CFI(TBI) assembly
• G – Fuel Line to CFi
• H – Fuel Filter
• I – Cold Start Injector Pipe Port
• J – CIS diagram & instructions, PP.18-19
• K – See GM TEl diagram & instructions, pp. 16-17

ADAPTER APPLICATION & SPECIFICATION CHART

FUEL PRESSURE RELEASE

some models may have two fuel pumps, in tank and outside. Unplug both.

Disable in other ways:

• Audi
  Coup & V8 Quattro : unplug fuel pump connector. All others:remove fuel pump relay.

• BMW
  Through 1990:Disconnect negative terminal of fuel pump.
  1991:Unplug fuel pump connector.

• Ford
  Cars, vans, and utility vehicles except Explorer:Disconnect inertia switch.
  Explorer: Unplug fuel pump connector.
  Some Ford products have two fuel pumps.It is important that both fuel pumps are disabled.

• GM
  All except below:unplug fuel pump connector.
  (a) 1975-80 Cadillac: Disconnect one fuel pump in gas thank and second one on chassis, left front of tank.
  (b) 1986-89 Corvette:Remove fuel pump fuse if one fuel pump.If two tuel pumps, remove the correct 10 amp. fuse in both the main and auxiliary fuse blocks.

• Mazda
  MPV, MX-6, 626, Rx7, 323,929, & Navajo:Unplug fuel pumpconnector.
  B2600,MX5, & Miata;Disconnect circuit opening relay connector.

• Mercedes-Benz
  Disconnect negative terminal of fuel pump connector.

ADAPTER APPLICATION & SPECIFICATION CHART

To the best of our knowledge, the following data is accurate, but if in doubt,consult the shop manual for the car.Some models may take another adapter and the connection may be different. In very limited cases,there may not be an adapler for a particular model or year.

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