Mercedes-Benz W210 E-Class Fuel Pressure Regulator Replacement

Fuel pressure regulators are an occasional source of frustration for the do-it-yourselfer. Sometimes, they don't show any obvious indication of failure, leaving you puzzled when your car stumbles on acceleration. Testing a regulator can be a bit difficult as sometimes the fault won't appear until the car has reached a certain temperature. The first step in diagnosis is to go over the basics. Is the fuel pump operating? Is the fuel filter clogged? Is there actually any fuel in the vehicle? Believe it or not, many people overlook these steps. The next step in determining if the regulator is bad is to check the fuel pressure on the car. There are basically two ways to do this. You can use the test port on the fuel rail itself which requires you to rig up a Schrader valve type connection to a pressure gauge, or you can rig up a pressure gauge in-line down by the fuel filter. Either way you do it, make sure you have a gauge that is rated for fuel injection pressures (at least 50psi) and that all connections to the gauge are correct. Turn the key on and off several times to energize the fuel pump. This will build up pressure in the fuel rail and begin to register on the gauge. The system operating pressure is 35-40psi. If the operating pressure is below 35psi or fluctuates wildly, it's probably a good bet that the regulator is bad. If you pull off the vacuum connection and there is fuel dribbling from the nipple, the diaphragm inside has failed and the regulator must be replaced (this was the case on our project car). Be prepared: Work in a well ventilated area. Keep a fire extinguisher near you at all times and know how to use it correctly. No sparks or open flame around. We will be working around gasoline here. It's better to be prepared than have that one time where everything goes wrong. Read the Full Article: https://www.pelicanparts.com/techarti... Time: 5 min Tab: $150 Tools: 13mm wrench :https://www.pelicanparts.com/Mercedes..., circlip pliers :https://www.pelicanparts.com/Mercedes... Applicable Models: Mercedes-Benz E320 (1996-97) :https://www.pelicanparts.com/catalog/... Parts Required: New pressure regulator :https://www.pelicanparts.com/cgi-bin/... Hot Tip: Check system pressure before replacing regulator Performance Gain: Car runs like normal again Complementary Modification: Replace fuel injector seals