Checking For Leakage

Checking for Leakage




1. Detach electrical wire from the control pressure regulator for warm running compensation. using a jumper wire, connect the control pressure regulator for warm running compensation directly to B+ (fuse box on left side of engine compartment).

Turn selector valve to position 2 and switch the ignition on.

Having attained the "warm" control pressure value (part-load value), switch the ignition off again and observe the pressure drop on pressure gauge (the pressure will drop considerably first). If the pressure continues to drop too rapidly (see testing and adjustment specifications), repeat check in position 3 of the selector valve to locate the problems. If the same results are obtained, four components can be responsible:
electric fuel pump
Fuel distributor
injection valves
start (enrichment) valve

Injection valves and start valve are judged in separate tests. Replace electric fuel pump and seal of pressure relief valve in fuel distributor one after other and repeat each test.

If leakage does not occur in 3 position of the selector valve the problem can be in the control pressure regulators for warm running compensation or throttle valve position.




To locate the problem, switch the ignition on until control pressure has built up, then switch the ignition off again. Detach return hose from the control pressure regulator for warm running compensation. With the remaining pressure being 1.5 to 2.4 bar, no fuel should come out from the return connector of the control pressure regulator for warm running compensation

If some fuel should be coming out, it would indicate that the control pressure regulator for warm running compensation is leaking and should be replaced in such case.

If the leak is not in the control pressure regulator for warm running compensation, it will be found in the control pressure regulator for throttle valve position, in which case the control pressure regulator for throttle valve position will have to he replaced.