If you don't know where the injection pump is, it might be difficult for you to diagnose this problem correctly and you may want to bring the car to a mechanic who knows Mercedes. What needs to be done first of all is to examine the whole engine for fuel leaks. This includes the IP, all the fuel lines running between the IP and the fuel filter, and all the injector hoses that are hiding under that black, plastic cover. Second, while the crossover intake pipe is off (it'll need to be off to remove the black cover) the flaps in the intake need to be cleaned and lubed. That should take care of your running problems. If not, there are other things that can be done.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL