I am doing an EFI conversion on a 408 cu in Ford 400 motor in a 1953 F100. I am using a 2003 Cobra TB mounted on a Ford 460 EFI upper intake.
I bought a used BBK Cold Air Kit for a 2002 Lightning. It seems to be all OK, but I will have to fabricate some parts. I also have a 90mm Lightning MAF.
In the Intake section that attaches to the TB, there are 4 holes. Two holes are in the bottom of the air section. I believe that the larger of those is the air temp sensor. Another hole has a large hose attached. The fourth hole is in the side of this air section.
Iím not familiar with the BBK Cold Air Kit, but normally you have right and left side PVC returns plumbed into the two large bottom holes, a small vacuum line (not sure where it runs) in the small bottom hole, and the IAT sensor in the side hole.
OK, I figured the large hose was the PCV valve connection. My IAT sensor fits the large bottom hole(Grommet), but not the side hole. The small hole, I can plug, if not needed. I can drill the side hole, if necessary.
Why is there two PCV connections? When the PCV valve opens it draws fresh air through the crankcase from the valve cover filter.
Do I have to run this back into the air intake to get it through the MAF? The pressure will be the same on both.
I think that I have it figured out. I took a peek at the air system on my 4.6L in my Mountaineer.
The PCV valve is plumbed to manifold vacuum (same as a carb). The valve cover air inlet is plumbed to the air intake, so that the crankcase fresh air goes through the MAF. The large hose supplies the air to the Idle Air Control, this is also through the MAF.
I think that I am covered, if I can find a valve cover vent cap that has a hose fitting.
The filtered vent cap that I now have won't work.