Fuel Injection - Quantity, Comparative Measurement
91audi04
Group: 25
Number: 91-08
Date: June 30, 1991
Subject:
Viton Tipped Fuel Injectors, Injection Quantity, Comparative Measurement
Model(s): All with CIS, CIS-E, CIS-E III m.y. 1985-1991
This procedure for comparing fuel injection quantities applies to the following Audi vehicles if equipped with Viton tipped fuel injectors:
All 4000 1985 - 1987
All 5000 1985 - 1988
All Coupes 1985 - 1988
All 100 1989 - 1991
All 200 1989 - 1991
All 80/90 1988 - 1991
- check part number stamped on barrel of injector
Note Two types of fuel injector are used in these vehicles: Viton tipped and metal tipped. 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 metal tipped, check using procedure in Repair Manual, Group 25, Section 25-55
CAUTION
Part numbers are for reference only. Always check with the Parts Department for the latest information.
Notes regarding Viton tipped injectors:
^ They can be used as a replacement for metal tipped injectors but only in complete sets
^ The fuel absorption characteristics of Viton requires different testing considerations than metal tipped injectors
Remote control VAG 1348/3A, connecting
Requirement
^ Fuse 13 OK
- remove fuel pump relay (J 17) from fuse
relay panel, position 10
- connect adaptor wire VAG 1348/3-2 to terminal 52 in fuse relay panel
- connect alligator clamp from VAG 1348/3A to battery plus or to B+ on alternator
Injection quantity, comparative measurement
- ensure that all fuel lines are tightly connected to injectors
- insert fuel injectors into analyzer
VAG 1348/2
CAUTION
Carefully route the fuel lines to avoid pinching and bending. Unclip the fuel lines if necessary.
Rest position (idle), quantity comparison
- turn screw 1 and nut 4 of tool VAG 1348/1A until slide 2 is in upper position
- place tool centrally on edge of airflow sensor as shown
^ pointer 3 must point toward fuel distributor
- position airflow sensor plate (by hand) in the rest position
- rotate adjusting screw 1 until tool magnet contacts sensor plate mounting screw
^ while sensor is at rest position
- rotate nut 2 downward 15 mm (0.6 in.)
- operate remote control for 20 seconds
- while holding analyzer level, compare fuel quantities in each tube
^ maximum permissible difference between the entire set of measurements must not be greater than 2.5 ml
If fuel quantity in tubes differs between a high and low of 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 those injectors
Full throttle position, quantity comparison
- drain VAG 1348/2 fuel analyzer
- rotate nut 2 downward 30 mm (1.2 in.)
- operate remote control for 20 seconds
- while holding analyzer level, compare fuel quantities in each tube
^ maximum permissible difference between the entire set of measurements must not be greater than 8.0 ml
If fuel quantity in tubes differs between a high and low of more than 8.0 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 those injectors