Fuel System - Pressure Pulsating Noise
CATEGORYEngine
SECTION
2
PAGE
29
ISSUE
04/93-0320
CODE
234
Subject:
Pulsating Noise From Fuel System
Application:
9000 Models with B234 Engine
It is possible that the spring-loaded damper fitted to B234 engines may not dampen all pressure pulsations in the fuel system. Under the following conditions a customer may complain of pressure pulsation noise:
^ When idling with a hot engine
^ When starting from cold. It may sound as if the fuel lines are knocking against the undercarriage of the vehicle. This noise will disappear once the engine has warmed up.
A new damper has been developed to remedy this complaint.
If the steps taken in PSI 10/91-0145 do not rectify a complaint of fuel pulsation noise, an extra damper can be fitted in the fuel system's return line.
Cars Affected:
1990 1/2- 9000 models with B234 engine
Parts:
Mounting Kit (B234 Turbo) 93 21 894
(Consisting of:
Damper 93 21 886
Clamps [21 79 77 697)
Mounting Kit 93 21 902
(B234 Naturally aspirated)
(Consisting of:
Damper 93 21 886
Clamps [4] 79 77 697
Connectors [2] 83 21 556
Hose [2] 93 63 300)
WARNING!
Always observe the following safety precautions when working on the fuel system:
^ NO SMOKING!
^ Have a fire extinguisher nearby.
^ Wear Eye protection.
^ Work in a well-ventilated area. Use Vapor extraction equipment if available.
^ Avoid prolonged skin contact with fuel and wear suitable gloves.
Action:
Before disconnecting any fuel line, remove fuse # 14 and start the engine, allowing it to run until it stalls. This will purge the system's fuel pressure.
For B234 Turbo engines:
1. Disconnect the return line at the fuel distribution pipe.
2. Measure 145 mm up from the end of the return line. Using a sharp knife, remove a 50 mm section of hose. (See Figure 1.)
3. Fit two spring clips on the rubber hose.
4. Fit the damper and adjust the spring clips to the correct position.
5. Reconnect the return line.
6. Check that there is sufficient clearance around the damper and fuel line.
7. Refit fuse # 14 and re-start the engine. Verify that there are no leaks.
Action:
Before disconnecting any fuel line, remove fuse # 14 and start the engine, allowing it to run until it stalls. This will purge the system's fuel pressure.
B234 Naturally aspirated:
1. Remove the inlet hose from the throttle housing. Disconnect the return line at the pressure regulator.
2. Using a sharp knife, cut a section of the plastic hose 140-150 mm as shown in Figure A.
3. Using fuel line grip 83 94 546, fit two connecting nipples in the plastic hose as shown in Figure B.
4. Connect two rubber hoses and fit four spring clips as shown in Figure A.
5. Fit the pulsator and adjust the spring clips to the correct position.
6. Reconnect the return line.
7. Check that there is sufficient clearance around the damper and fuel line. Refit the inlet hose to the throttle housing.
8. Refit fuse # 14 and restart the engine. Verify that there are no leaks.
Warranty Information:
For warranty repairs where the owner is not satisfied with the repair in PSI 10/91-0145, use Failure Coding 24143-71-0-01-10. Labor time allowance is Operation No. 24143 (0.2 hours). Add 0.1 hour in straight time for B234 Naturally aspirated vehicles.