Hello everyone! Yea, I was reading about adjusting the fuel pressure regulator for a little fuel enrichment on my 92 300E, unfortunetaly, the original thread's links to pictures does not work. Can anyone tell me where this "box" is located, or supply some pictures? I opened somethign that I supposed could have been the box under the air filter housing, and some fuel started leaking, so I quickly closed that back up....

come on now... somebody must know.. my car is sitting around with the air filter off, and id like to do something before I put it back on....

The fuel pressure regulator on the M119 engine, at least, is not adjustable. It is a cylindrical brass doodad, about 1.25 inches in diameter with a vacuum hose coming off the top of it, and sits at the rear of the engine on the driver's side. They do go bad at times and cause rough idle conditions, and probably other symptoms.

Don't know if this applies at all to the 300E.

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Steve
'93 400E

well your probably right, and im probably just dumb, what it was described as was a black box that controlled the lower chamber pressure and adjusting it would yield a richer fuel mixture. Now, I assumed this was the fuel pressure regulator, but Im probably wrong on that. The thread is here http://www.peachparts.com/shopforum/showthread.php?threadid=34888 so maybe somebody can figure out what this part is....

That post is about the EHA (electro-hydraulic actuator, I think that was it's full name). It is the black box connected on the side of the fuel distributor. Hope this helps

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

hrmm... well then that is the thing I adjusted, is it normal for fuel to come gushing out when you loosen the two retaining screws? And how do I keep from emptying my gas tank? Or is it just the left over fuel pressure from when the engine was on?

I don't think you did damage to the EHA since you can't adjust those. Since you said in your original post that you close back up whatever you tried to adjust(most likely the EHA), you can retighten the two screws and start the car and check for leaks. You can leave the air filter housing off if you want. If there is a leak, its probably gonna come from the two small o-rings between the EHA and the fuel distributor. Easy fix. Good luck.
To answer your question on the fuel gushing out, it is residual fuel but still under pressure. You ca relieve some of the pressure by opening the gas cap.

yea... I retightened it up and nothing leaked. I did clean out the engine with a lot of water.. hand poured I might add... just in case my engine wanted to catch on fire. But now, you mentioned that the EHA isn't adjustable??? Are you sure?

There is a screw inside the EHA which is used to rise and lower the fuel pressure.

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)