EFI Vacuum Lines Picture - Under Side Upper

[rguest3]

Looking for a picture or diagram of the Vacuum lines on an EFI 5.0/5.8 with GT40 intake. Non EGR.

Have not installed one of these in awhile and need a refresher as to where all vacuum lines plug into the manifold. I even have most of the original lines in great condition and want to use them.

Are they ALL full vacuum? I realize some ports will be plugged off and not used.

PCV
Fuel Regulator
MAP
Power Brakes
One from Valve cover to Throttle body.

Thanks

 

[70_Steve]

Don't know that a diagram is required.

Yes, all listed get full manifold vacuum, except possibly the MAP. A MAP is used on Speed Density systems. If you have a Mass Air system (if you have a MAF) then the MAP gets replaced by (turned into) a BP (Barometric Pressure ) sensor. The same sensor as the MAP, but does not get connected to a vacuum source. Just left open to the atmosphere.

And the line from the throttle body to the valve cover is the fresh air source for the PCV system. It is not under vacuum.

 

[DirtDonk]

I'll add too, that the diagram is hard to come by (or pics for that matter) because even those of the same engine/vehicle, have completely different orientations it seems, from year to year.
And the different vehicles? Fuggetaboutit.

And yes, every vacuum port on, under or around the upper manifold/plenum, no matter what it's size, is full manifold vacuum.
So if you have six ports, just use the ones that are most convenient for you. PCV and brake usually get the large ones, pressure regulator gets the smallest.

Paul

 

[6daze]

Here is mine, more pics in my build thread.

I originally put plastic caps on all unused ports. Within 6 months they all cracked and started to leak. I suggest tapping and plugging anything you don't use.

I only used vacuum for the fuel pressure regulator.

Mark

 

[DirtDonk]

What he said. All the plastic and rubber caps you buy from the local auto parts store are crap. Absolute crap.
Even without running the engine, they will deteriorate right in the garage once they're out of the package.

Been through several changes between me and my buddies. Some rubber hoses too.
Changing to vinyl/plastic vacuum line and, if I can't source factory original rubber caps and elbows, I'm just pulling the tubes, threading and capping the holes, like 6daze said.

Just did it on a friend's upper and it worked out well. But be ready for a fight. Some of those tubes are really in there and do NOT want to come out.

Paul

 

[rguest3]

Since all the Ports are Full Vacuum, and it does not matter which one to use for whatever, I'll see what makes it work the best with the OEM Vacuum lines.

Will look stock when done.

Thanks for the help.

 

[73azbronco]

you have to remember all those ports are there to match up with some specific component in that location, that's why it looks like a maze. I would be cautious and use a dedicated line to FPR, it is sensitive, and one to brake booster, it uses lots of air.

 

[rguest3]

Got that taken care of already.

Thanks