Originally Posted by Benz Mondi

Smell of gas is the classic sign of a leaking EHA valve. Lift off the air cleaner, it's the black box slightly larger than a match box that is bolted on the side of the fuel distributor (the spider looking silver mound that all the rigid fuel hoses go to). Turn the engine on and you'll see fuel leaking out of the weep holes. Good news is that there are plenty of good used ones on eBay for $80 of less (make sure you get a leak-free warranty). You'll also want to get a new pair of O-rings ($7.95). Don't try to find some cheap a/c O-rings as poor substitutes or re-use the old ones. They'll just leak again. EHA O-rings are made of a special compound and are of a specific size that doesn't match anything you can find locally.

Removal/installation is easy: 1) with the engine not running, put a cloth underneath the EHA to soak up the small amount of fuel and, more importantly, the bolts and O-rings that you'll surely drop and never find in the depth of the engine. Unplug the electrical connector at the side of the EHA. Some of the bolt heads require a Torx (should be a T-30) or standard flat head screw driver. If it's a Torx, make sure you use the correctly fitting one. You don't want to strip this. It usually takes more torque that one would think to turn the bolt. BEFORE, you attempt to turn the first bolt, take another cloth and cover the top side of the EHA while you turn the bolt. Otherwise you are sure to get a shot of gasoline in the eyes. Loosen each bolt until the gas leaks out and the pressure is gone. Then unbolt the EHA the rest of the way. Inspect the replacement EHA mating surface to make sure it's completely clean and flat. The same for the mating surface at the fuel distributor. Remove the old green O-rings from the fuel distributor with a pick. Install the new ones, making sure the completely fit inside the recessed cavities. Carefully bolt on the EHA, making sure you haven't dislodged the O-rings. You just need to "hand-tight" the bolts. The fuel pressure will make the fit tighter. Clear the area of the cloths and tools. First turn the key to the on (do not start the car) to pressurize the EHA and check for leaks, then turn the engine on. It should not only idle well, but should not have any leaks. Keep the engine running for at least 5 minutes and increase the RPM's to 2,500 for at least 30 seconds to check for leaks. Done!