pcv valves
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Joined: Jun 2003
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pcv valves
This seems like it should be simple, but I can't figure it out, so I'll put it out there for you all. Just getting finished with my 66 F100. Did the disc conversion, new front end bushings, etc.... Swapped in a 351m that I had, it was better than the 360 that was in it. Only problem is the PCV valve. If I hook it up to the port at the back of the intake, all I get is a vacuum leak, with a noticeable change in idle quality. Plug the valve, leak goes away, idle returns. Bought a new PCV, checked for other leaks, etc.... The vent is hooked to the air filter, no restrictions there. What am I missing here? Am I hooking it up to the wrong place? I tried another vacuum port with the same results. Any ideas are appreciated.
Dave
Dave
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Joined: Aug 2000
Posts: 1,127
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From: (near) Denver USA
pcv valves
The PCV valve requires manifold vacuum to work.
Usually, it goes to a port at the bottom of the carb, or to a spacer under the carb, so the blow-by gasses are distributed evenly among all the cylinders.
If you have idle problems with the PCV hooked up to a central manifold vacuum source, you need to re-tune the carb to idle properly with PCV.
Usually, it goes to a port at the bottom of the carb, or to a spacer under the carb, so the blow-by gasses are distributed evenly among all the cylinders.
If you have idle problems with the PCV hooked up to a central manifold vacuum source, you need to re-tune the carb to idle properly with PCV.
Post Fiend
Joined: Jan 2003
Posts: 10,323
Likes: 2
From: Montana Territory
pcv valves
You have to have an air return to the crankcase. Check to make sure that its not plugged. Inside the air filter housing is a housing for the crankcase airfilter the filter might look clean but the tube could be plugged.
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