What is the purpose of the black hose that comes from the top of the back of the valve cover and runs to the back left bottom of my weber carb, I seem to be getting a small amount of oil residue in my carb and its coming from this line, can I plug both ends and stop this or am I about to cause a bigger problem thanks for anyones input

It's the other end of the pcv system. The valve is the suction side, and the hose you refer to is to allow air into the crankcase system to replace what the pcv valve allows to be sucked out. You can install a small filter on it and plug the carb side. Where are you routing the pcv valve?

Ok Eddie let me see the pcv valve is located on the front of the valve cover with a black hose running from it to the intake below the carb, and the hose I am referring to runs from a nipple on the back top of the valve cover and connects to the chrome plate on the bottom of the weber air filter, this is where I am seeing the oil residue inside the inner part of the filter where the white nipple is screwed into the chrome plate, what your saying is I cannot just plug the white nipple under the chrome plate and plug the nipple on the back of the valve cover.....I was thinking the carb suction was pulling oil out of the valve cover causing my problem...I dont understand what you mean by where am I routing the pcv valve...... I cant leave it where it is?

Strange...on my '89 Monty with the 32/36 Weber conversion, the only hose I had running to that base plate on the Weber air filter was the one from the black canister by the right headlight. As has been mentioned, I put a breather filter on the fitting on the rear of the valve cover, and when I replaced the rectangular open air filter with a snorkel-type fitting, that wasn't machined for any hoses, I stuck another breather filter into the end of the hose that used to go into the base plate of the Weber air filter. Seems to run fine either way...

The pcv valve hose has to go to manifold vacuum, so that's right. The hose to the rear of the valve cover is the inlet side of the pcv system, it lets air into the crankcase to make up for the air the pcv check valve allows to be sucked out. It routes to the air cleaner because you don't want unfiltered air going into the crankcase. If you put a small air filter on it and plug the nipple on the air cleaner, all is good, no oil into the air cleaner, clean air into the crankcase. The 2.6 used to have a jury rigged air pump to pump air into the exhaust. The pump was contrived by walling off the bottom of #3 cylinder and putting a checkvalve on the side of the block, and using the bottom of the piston as a pump, so the crankcase is not well ventilated and you get pressure pulses out the pcv intake hose sometimes, thus the oil in the air cleaner.

The 2.6 is a real dinosaur of a motor, going back to the early days of emissions controls, and it has some quirks as a result. It's been used as a propane forklift motor, a marine engine, and a turbocharged rocket motor in addition to passenger car and truck duty.

I appreciate the info Eddie, I'm going to get a filter for the back of the valve cover nipple to let it get air and plug the base plate nipple on the weber filter with a bolt..thanks again for the info