I have a 1986 Bronco w/ 351W HO. The hose from the PCV to carb has a valve on it with a lever that turns. I'm assuming it controls how much that connection is open. Anybody know if this was a stock thing on this vehicle or if some mechanic did it for some reason? Is there any reason why you would want to control the flow from the PCV to the carb this way?

 

As smog equipment goes verses performance, the EGR valve is one of the nastiest, but it also has a very positive effect in cleaning the air. However, most engines designed to run properly with an EGR valve have carburetors and timing controls that, when the EGR is disconnected, actually cause the engine to run poorer and often hotter.

Sounds to me like someone installed a cutoff to try and improve performance and still be compliant at smog test time. Or perhaps it was installed to assist in timing or some other vacuum test. But there are better ways!

 

Ah Polkat, He said PCV not EGR. I have never seen one with a lever on it. Don't know.

 

Dang if he didn't!!? Err...what day is this? Oh...wait! Forgot my glasses. Yep, he sure did!

As far as a lever on the pcv valve...beats me! Maybe it's the same reason though...perhaps a previous owner was getting a lot of blow bycausing a lot of oil to get into the carb.

Gendoikari, was that happening? All I can say is that it isn't stock.

 

the blow by theory sounds most sound to me. Every one hates a gunked up motor.

 

I don't know if he had blow by or not. I took the hose apart and the valve actually did not cut off the flow. A small hole extends up into the valve to where the lever attaches, but there is nothing in the lever's housing that seems to cut off the flow. Who knows what it did.

 

Well, here's another theory: The previous owner was super cheap! He did some kind of repair and found he didn't have enough hose to make it from the carb to the valve, so he used two shorter hoses and the valve acted as a junction!!

Get yourself a proper length of hose and replace it. Trust me, you won't hurt anything!

I've found a lot of weird stuff in cars I've bought over the years. For example, I bought a '49 Nash about 20 years ago with the idea of restoring it (it was complete and sitting in a farm field). I found a beer tap mounted in the top of the ashtray!! I discovered that the previous owner used to mount Tap-A-Kegs (5 gallon metal beer kegs that were popular some 25 years ago) in his truck, then run a rubber hose from it to the tap in the ashtray so he could guzzle as he cruzed around!

A '67 F-100 I used to own came with a large plastic Coke bottle mounted in the big oil type air cleaner. The owners fuel tank lines clogged up, apparently from rust one day, but he had a can of gas in the bed. He filled the bottle with gas, poked a little hole in the bottom, and struggled the truck home on the bottle's leak!! He never bothered to remove it.

My present '73 F-100 still has a working garden hose valve mounted in one of the heater hoses. Apparently at one time the heater leaked and the regular valve didn't work. I fixed the heater but haven't yet fixed the valve, so I leave it in for now.

Maybe we should do a post on what weird things people have found in their older trucks!? Polkat