System (Line) Control Pressure Test
- Close valve on pressure gauge. With engine off, operate fuel pump. Pressure should rise to level specified in "Pressure Testing" chart.
- If pressure is too low, check fuel pump output. Disconnect fuel return line from fuel distributor and run a hose from fuel distributor to container. Operate fuel pump and measure output after 30 seconds. If not as specified in "Fuel Pump Flow" chart, check fuel lines, filter, accumulator and pump.
Fuel Pump Flow Specifications
| Application |
Flow in 30 Sec. ox. (cc) |
| BMW, Peugeot, Porsche |
24 (750) |
| Audi, Saab, VW |
30 (900) |
| Mercedes-Benz |
32 (1000) |
- If pressure is too high, check for kinked or blocked fuel return line. If lines are clear, system pressure regulator must be adjusted. Turn pump off, loosen return line fitting, and relieve pressure.
Courtesy of NOT AVAILABLE
- Loosen line pressure regulator nut. Remove shims, spring(s) and plunger. Raise system pressure by adding shims; lower pressure by removing shims. Be sure "O" rings are in good condition. If plunger is scored or damaged, fuel distributor must be replaced.
FUEL INJECTION PRESSURE TESTING
| Application |
Line Pressure psi (kg/cm2
) |
Warm Control Pressure psi (kg/cm2
) |
Rest Pressure psi (kg/cm2
) |
Nozzle Opening Pressure psi (kg/cm2
) |
| Audi 5000 Turbo |
72-81 (5.0-5.6) |
49-55 (3.4-3.8) |
23-37 (1.6-2.6) |
38-53 (2.7-3.7) |
| Audi 4000, 5000 |
64-74 (4.5-5.2) |
49-55 (3.4-3.8) |
23-37 (1.6-2.6) |
41-59 (2.9-4.1) |
| BMW 320i |
64-75 (4.5-5.2) |
49-55 (3.4-3.8) |
24(1.7) |
44 (3.1) |
| Mercedes-Benz |
72-81 (5.0-5.6) |
49-55 (3.4-3.8) |
36-41 (2.5-2.8) |
43 (3.0) |
| Peugeot 505 |
64-75 (4.5-5.2) |
49-55 (3.4-3.8) |
38-39 (2.6-2.7) |
43-59 (3.0-4.1) |
| Porsche 911SC |
64-75 (4.5-5.2) |
38-44 (2.7-3.1) |
|
|
| Porsche 924 |
64-75 (4.5-5.2) |
49-55 (3.4-3.8) |
21-24 (1.5-1.7) |
36-52 (2.5-3.6) |
| Porsche 924 Turbo |
78-87 (5.4-6.0) |
49-55 (3.4-3.8) |
14 (1.0) |
38-55 (2.7-3.8) |
| Saab |
64-75 (4.5-5.2) |
49-55 (3.4-3.8) |
24-34 (1.7-2.4) |
43-59 (3.0-4.1) |
| Volkswagen |
64-75 (4.5-5.2) |
49-55 (3.4-3.8) |
23-37 (1.6-2.6) |
46-54 (3.2-3.8) |
| Volvo 4 Cyl. |
64-75 (4.5-5.2) |
50-56 (3.5-3.9) |
24-34 (1.7-2.4) |
37-51 (2.6-3.6) |
| Volvo 6 Cyl. |
64-75 (4.5-5.2) |
45-49 (3.1-3.4) |
24 (1.7) |
37-51 (2.6-3.6) |