Injector failure causes engine starting difficulties (both cold and heated), transient disturbances and high fuel consumption.
The thermal time switch limits the injection time of the cold start injector depending on the engine temperature.
To remove the cold start injector, perform the following operations:
Disconnect the injector connector (98).
Disconnect the fuel hose from the injector.
Caution: If the injector is removed only for inspection, the electrical wire and hose remain connected.
Remove the injector by unscrewing 2 nuts.
To check the cold start injector, perform the following operations.
Connect the brown/blue wire of the thermal time switch to ground, this simulates a lower engine temperature
Caution: Do not connect the pink/blue wire to ground. Risk of short circuit!
Place a measuring cup under the nozzle.
Disconnect the connector of the transistor ignition system switching unit to prevent the engine from starting.
Turn on the starter briefly. The injector should provide a uniform cone of fuel injection.
After the starter is turned off, not a single drop of fuel should appear from the injector for one minute. The injector should be dry on the outside,
To install the cold start injector, perform the removal operations in reverse order.
Attention: Be sure to replace the injector gasket with a new one.
(Original article is on the portal: MercedesMAN)