Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi, my name is***** can I help you with?
Hi, sorry for the trouble with the site this morning. If both pumps work but you don't get any fuel pressure the problem would have to be inadequate flow from the tank to the pump. You might have flow initially but it may be slowing down to a trickle as the pump tries to draw fuel from the tank. I'd have to suggest that you check the screen in the tank and see if it is plugged.
Sounds good. Let me know how you make out.
If the fuel poured out for awhile the problem shouldn't be the screen. If that is the case then the problem would have to be with one of the pumps. I'm assuming that your pressure gauge is working properly. You should have 52 psi fuel pressure at the fuel rail when cranking the motor.
That's not really a good test. You need to measure the pressure at the fuel rail. If you don't have 52 psi when cranking one or both of the pumps must be bad.
Weber is not the OEM pump for that car. I would question their compatibility. Bosch pumps are the OEM pump. I would not trust anything but Bosch.
If you have fuel from the tank to the first pump but you are not getting any fuel pressure I would have to say that the pumps are not suitable for this application or they are wired backwards. Switching to the OEM pump should solve the problem. Check your wires first and make sure you connected them properly. The brown wires go to the negative terminal on the pumps.
It's got to be a problem with the flow from the tank. The screen in the bottom of the fuel tank unscrews but it can be difficult to access. Follow the main hose up to the tank and unscrew the hose and the screen. If you just pull the main hose to the first pump you should be able to drain the entire tank before you remove the screen. If you find that the flow from the tank slows down to a trickle it would indicate a plugged screen but if the tank drains fast from the hose the problem has to be with the fuel pumps. If the gauge is not reading correctly I'd try adding at least 5 gallons of fuel to the tank and see if it will pump fuel before I drained the tank.
Hi, I'm just following up with you on the Mercedes. Did you ever get it running?
Great! What turned out to be the problem? If my information was helpful I would appreciate it if you would click on a rating for my service as this is the only way that I can receive credit from the website.