2004 C 240 fuel pressure loss
 

Hi all!! I am hoping that someone out there has experienced this problem before. The case is a C240 that has a fuel pressure loss after two days of sitting without starting. If the car is driven or at least started everyday there isn't any problems starting the car. I confirmed that over the weekend with a fuel pressure guage connected I had 0 psi Monday morning. I tried to start the car and after the first tip start I recycled the key once more and the car started but ran slightly rough until the fuel pressure was equalized at all of the injectors. I think I may have a bad fuel pump not holding pressure after long periods of sitting or a bad filter in this case. I heard that some filters were designed to have the ability to keep fuel from bleeding back to the tank. I also noticed that when it started that there was more smoke than normal ( it seemed ) that was coming from the exhaust. Possible injectors leaking in the cylinders causing the fuel pressure loss? Thanks for any help in this matter.

Only bleed off points are the fuel pump, filter, or in the injection rail.

Pump OR filter is the most likely.

You don't mention mileage, but without looking at the WIS I believe the filter is a 60K item. And it incorporates the pressure regulator, so that's the first thing to look at.

It's a basic DIY item, just get some clic-pliers for the clamps and some bar-type clamps to close off the fuel lines.

Thanks for the replys!! I will change the filter first.