"VITON" Tipped Injectors
***UPDATED BY TSB #259108.NOTE: Two types of fuel injector are used in these vehicles: Viton tipped and metal tipped. Viton tipped injectors can be used as a replacement for metal tipped injectors but only in complete sets. Check part number stamped on barrel of injector. Viton tipped injectors will have one of the following Bosch part numbers stamped on the barrel of the injector:
0-437-502-043 High pressure (replacement)
(Audi replacement, Part Number 035 133 551F)
0-437-502-044 High pressure (OEM)
(Audi replacement, Part Number 035 133 551F)
0-437-502-045 Low pressure (replacement)
(Audi replacement, Part Number 026 133 551)
0-437-502-046 Low pressure (OEM)
(Audi replacement, Part Number 026 133 551)
If injector does not have one of these part numbers, it is a metal tipped injector. Use testing procedure for metal tipped injectors.
CAUTION: Part numbers are for reference only. Always check with the your local Audi dealer parts pepartment for the latest information.
The fuel absorption characteristics of Viton requires different testing considerations than metal tipped injectors. This procedure applies to all Audi vehicles equipped with CIS fuel injection systems with "Viton" tipped fuel injectors.
SET-UP
Fuel Pump Relay Socket Terminal ID:
1. To operate fuel pump when needed, remove fuel pump relay and connect remote switch to relay panel terminals 48 and 52 (see illustration).
2. Remove intake manifold upper section (if necessary).
3. Remove fuel injector retaining bracket and pull injectors from manifold leaving fuel hoses attached.
Comparing Injector Quantities:
4. Fix injectors into graduated cylinders or other measuring containers such as that shown in illustration. Be careful not to kink any lines. Make sure that all fuel lines are tightly connected to injectors.
5. Position adjusting tool #VW 1348/1A on top of air cone (see illustration).
6. Back out adjustment screw (1) and nut (4) all the way, push slide down to bottom and screw adjustment screw in until magnet just contacts bolt at center of sensor plate. It may be necessary to turn the slide nut down slightly so that the tool just contacts the bolt at center of sensor plate, with the slide nut bottomed against the tool body.
7. Turn fuel pump "ON" with remote switch.
8. Back out adjustment screw on tool to slowly raise sensor plate until injectors just begin to release fuel.
9. Raise slide (and sensor plate) approx. 1" momentarily to purge any air from the injectors and lines, then push back down to stop.
10. Turn fuel pump "OFF" and pour fuel out of graduated cylinders into a suitable container.
IDLE QUANTITY COMPARITIVE MEASUREMENT
1. Turn screw (1) and nut (4) of tool VAG 1348/1A until slide 2 is in upper position.
2. Place tool centrally on edge of airflow sensor as shown. Pointer must point toward fuel distributor.
3. Position airflow sensor plate (by hand) in the rest position.
4. Rotate adjusting screw (1) and slide nut (4) until tool magnet just contacts sensor plate mounting screw. Sensor plate should remain at rest position and slide nut should just contact the body of the tool.
5. Rotate slide nut downward to raise the sensor plate 0.6 in. (15 mm).
6. Operate fuel pump for 20 seconds.
7. Compare fuel quantities in each tube.
^ Difference between largest and smallest quantity must not be greater than 2.5 ml.
If difference between largest and smallest fuel quantity is more than 2.5 ml, interchange those two injectors and repeat test.
If quantity of injected fuel did not change after swapping injectors, check for a pinched fuel line or the possibility of a defective fuel distributor. Repair or replace as necessary.
If fuel quantity does change after swapping injectors, replace the injector(s) that deviates the most from the average quantity measured.
FULL THROTTLE QUANTITY COMPARITIVE MEASUREMENT
1. Pour fuel out of measuring containers.
2. Rotate nut 2 downward to raise the sensor plate another 1.2 in. (30 mm).
3. Operate remote control for 20 seconds.
4. Compare fuel quantities in each tube.
^ Difference between largest and smallest quantity must not be greater than 8 ml.
If difference between largest and smallest fuel quantity is more than 8 ml, interchange those two injectors and repeat test.
If quantity of injected fuel did not change after swapping injectors, check for a pinched fuel line or the possibility of a defective fuel distributor, repair or replace as necessary.
If fuel quantity does change after swapping injectors, replace the injector(s) that deviates the most from the average quantity measured.
NOTE: The fuel distributor control plunger can be checked for leaking while performing this test. Prior to checking injectors, remove air filter element from air cleaner box. When test is completed, check inside of air cleaner box for fuel. If any fuel is present, the control plunger is leaking into the air filter housing. The control plunger is not a serviceable part. If it is leaking, replace the fuel distributor.
INJECTOR O-RINGS (AIR LEAK TESTING)
1. Disconnect small air hose to intake manifold (air supply to air shrouded injectors).
2. Spray area around injectors with a mild solution of liquid dishwashing soap and water.
3. Connect air hose to air shrouded injector air supply port on intake manifold.
4. Regulate air pressure to 14psi (1 bar) gauge pressure and pressurize manifold.
5. Visually inspect area around injectors for bubbles. If any bubbles are present, the O-ring on that injector is leaking (un-measured air leak) and must be replaced.