Fuel Control System - Checking, Removal and Installation
86VW3
Applies To
GOLF, GTI,
JETTA, GLI
All With CIS-E
1985/1986
Group
25
Subject
CIS-E 1.8L Engine
Part Identifier
Key Points
Sensor plate, checking Control plunger, removing/installing Potentiometer, checking Full throttle switch, checking/adjusting A214
Number 86-01
February 14,1986
Sensor plate height, checking
Rest position, checking
Work sequence
- upper edge of air flow sensor plate must be below lower edge of air cone
^ a = 1.9 + 0.2 mm (0.075 + 0.008 in.)
Rest position, adjusting
Work sequence
- raise air flow sensor plate
- adjust position of sensor plate by bending wire clip (arrow)
CAUTION
Do not scratch venturi of air flow sensor. Do not bend leaf spring..
Air flow sensor plate free play, checking
Note Free play is noted between control plunger and sensor plate lever (right arrow). It is measured on side of air flow sensor facing fuel distributor (left arrow).
Test conditions
^ 4-16 mA differential pressure regulator current
^ conforms to basic adjustment of sensor plate lever
Work sequence
- actuate starter or remote control US 4480/3 for approx. 10 seconds to energize fuel pump
- slightly lift air flow sensor until resistance is felt
^ minimum clearance: feeling play
^ maximum clearance: up to venturi cone 2 mm (0.078 in.)
If clearance is NOT OK:
- remove fuel distributor
- perform Sensor plate lever, basic adjustment
- perform Sensor plate clearance, adjusting with control plunger stop screw
- reinstall fuel distributor and repeat clearance, check
Adjusting free play on fuel distributor
Work sequence
Varying measurement a:
- adjust idle travel of air flow sensor plate at stop screw for control plunger
(Distance a = approx. 0.6 mm (0.024 in.) between stop screw and flange of hex nut)
^ turn stop screw clockwise - clearance larger
^ turn stop screw counterclockwise - clearance smaller
^ 1/4 turn of stop screw - approx. 1.3 mm/0.05 in. difference on sensor plate
CAUTION
After adjustment, readjust idle speed and current reading mA (CO value).
Sensor plate lever, basic adjustment
Note
Always perform basic adjustment of lever when replacing fuel distributor or air flow sensor.
Work sequence
- check distance between contact surfaces for fuel distributor on air flow sensor and roller for sensor plate lever. If necessary, adjust via mixture adjustment screw
^ specification: 19.0 +/- 0.1 mm (0.748 - 0.004 in.)
Control plunger, removing/installing
Work sequence
- note measurement a before removing stop screw
- remove stop screw and detach control plunger
- clean control plunger with gasoline before reinstalling
- check sealing ring of stop screw for damage; if necessary replace (smaller diameter of sealing ring points to control plunger)
- turn stop screw back in to measurement a
- check and adjust rest position and clearance of sensor plate
Note
Mechanical cleaning of the control plunger is not permitted. If, after cleaning with gasoline, the control plunger is scored or sticking; the entire fuel distributor should be replaced.
Potentiometer, checking/adjusting
Note
Potentiometer is factory-adjusted. Retaining screws are sealed.
If potentiometer has to be replaced, adjustment must be done very carefully. Perform the following sequence to specifications:
^ sensor plate must be in rest position upper edge of air flow sensor plate must be below lower edge of air cone
^ a = 1.9 + 0.2 mm (0.075 + 0.008 in.)
- connect measuring wire VW 1501 to potentiometer (keep connector from engine wiring harness disconnected)
- connect digital multimeter US 1119 to adapter VW 1501 and check resistance on potentiometer terminals as follows:
Connect to terminals Resistance
1 + 2 greater than 4 K Ohms
2 + 3 less than 1 K Ohms
2 + 3 lift sensor plate evenly resistance
increases evenly up to 4 K Ohms
Potentiometer, adjusting
- lift sensor plate with VW 1348/1 up to lower edge (on fuel distributor side) of air flow sensor
- install potentiometer 1 and tighten screws just enough so that adjustment is still possible
- connect digital multimeter with measuring wire VW 1501
- set US 1119 switch to DCV 20
- turn ignition ON
- adjust potentiometer so that reading shows 0.2-0.3 Volt, then tighten retaining screws
- lift sensor plate up to stop; digital-multimeter US 1119 must show approx. 7 Volts
- seal screws with sealing compound or paint
Full throttle switch, checking and adjusting
- switch ignition ON
- open throttle valve completely
- measure voltage between connector (3) and adapter VW 1501
^ specification: approximately Battery Voltage
- attach pointer for 3084 to throttle body
- attach Protractor 3084 to primary throttle valve shaft, remove nut if necessary
- open throttle plate fully, and zero protractor
- close throttle valve approx. 20~. Slowly push back in the direction of full throttle (see arrow) until full throttle switch turns ON
^ specification 10~ +/- 2~. Before full throttle
- adjust switch point if necessary, by adjusting full throttle switch (5)
Note
Full throttle lever must lie on the diagonal of the full throttle switch lever.