Quantum L4-1715cc 1.7L SOHC (1983)
Technical Service Bulletin # 258806
Date: 881223
Fuel Injection - Cleaning & Intake Valve Decarbonization
GROUP
25
NUMBER
88-06 December 23, 1988
MODEL(S):
All VW's equipped
w/ CIS or CIS-E w/ air shrouded injectors
SUBJECT:
Fuel injection system cleaning and intake valve decarbonization
(Supercedes Tech. Info. 88-02, dated July 21, 1988)
Vehicles equipped with CIS or CIS-E fuel injection sometimes experience driveability problems such as rough idle, bucking or poor acceleration,
primarily during warm-up. Driveability problems are frequently related to the use of gasoline with insufficient cleaning additives which will lead to the
following conditions:
^
Fuel injectors and/or fuel distributor gummed up, fuel injector tips clogged by varnish and carbon deposits
^
Carbon build-up on intake valves and/or intake ports
This Technical Information Bulletin (broken into 4 steps) provides repair information to eliminate the driveability problems described above.
Step 1. Preliminary Checks, page 2 Step 2. Carbon Build-up Diagnosis, page 2 Step 3. Fuel Injection System Cleaning, page 4 Step 4. Carbon Build-up
Removing, page 8
Required Tools
-
VW 1367 Engine Tester
-
SUN 105 Exhaust Analyzer
-
flex light (high intensity)
-
inspection mirror
-
fuel injector insert removal tool US 1123
-
fuel injection system cleaning adapter kit US G16
Step 1. Preliminary Checks
-
test drive vehicle and determine engine performance
Check the following:
^
ignition timing point, correct if necessary
-
verify proper coolant temperature sensor 17~C to 45~C
P/N: 027919369B