couple .of efi questions

[blainebrazil]

88-93 mustang setup

On the lower intake what is the plastic port at the rear center of the intake for? It appears to have some sort of check valve in it.

On the underside of the upper intake there are 2 vacume lines and one has some sort of sensor on it. what are these for? There are also some larger threaded ports. 1 has a rubber hose attached to it and the other splits into 3 steel lines. 2 small and 1 a llittle larger. what are these for?

I also need to know what vacume line goes to the fuel pressure regulator? And where do I get the vacume for my power brakes and for c4 auto transmission.

any help is greatly appreciated

 

[Viperwolf1]

That's where the PCV valve goes.

 

[blainebrazil]

viperwolf,

i also posted a couple of more questions in my original thread maybe you can help me out with those.

 

[Greg_B]

Viperwolf knows much more than I but those other ports are simply vacuum ports. I used the large one for my power brake booster. One I used for the canister purge and one for the C4. I believe I plugged the other one off....

A Helm wiring and vacuum line manual if your friend if you have all the parts off of a Mustang.... then a vacuum line and wiring diagram for your year model Bronco is a must.

You can take those two manuals and learn a lot about what goes where.... then if something goes wrong you will understand what to look for and repair it yourself.

Greg

 

[Ourobos]

The port on the lower intake like mentioned, is the PCV port, a line will run from it to one of the larger ports on the upper intake. You really can modify or delete any vacuum trees/nipples you won't need. Other than the upper/lower PCV one, you'll need one large port on the upper for a source or brake booster if running power brakes. You will need one small nipple for your fuel pressure regulator. If you're running EGR, you'll need one small one for that.

 

[ransil]

always change the filter under the PCV valve ( screen looking thing) when using a used manifold. they will coke up and become hard as a brick and become clogged.

 

[blainebrazil]

thanks for the info. so correct me if i am wrong. All ports on the underside of the upper intake are vacuum. So I need 1 of the large hooked to the pcv on the lower intake, the other large for the power brakes, 1 small port for the fuel pressure regulator and 1 small one for my c4. other that that block the rest off. EGR delete

2 final questions. what does the nipple on the throttle body hook to? Do i need the sensor that is on one of the existing vacuum lines on the upper intake?

 

[ransil]

thanks for the info. so correct me if i am wrong. All ports on the underside of the upper intake are vacuum. So I need 1 of the large hooked to the pcv on the lower intake, the other large for the power brakes, 1 small port for the fuel pressure regulator and 1 small one for my c4. other that that block the rest off. EGR delete

2 final questions. what does the nipple on the throttle body hook to? Do i need the sensor that is on one of the existing vacuum lines on the upper intake?

that goes to the EFI valve cover, provides metered air to the crank case which is later evacuated from the crankcase via the PCV

 

[blainebrazil]

so do i have to use efi valve covers?

 

[HoosierDaddy]

HA , there is another thread going right now that is asking the same question.

The answer is : if you want it to run right , you have to use sealed (efi) valve covers. No breathers or leaks of any kind that will allow air from the outside atmosphere to penetrate or it will run like chit.







EDIT : Added the chit in red

 

[Steve83]

No, all EFI trucks have ported valve covers, which is what I put in Frank's '75, and it runs perfectly. Diagrams posted in the other thread.

 

[roan65]

EFI valve covers are shorter for clearance on Mustang type upper plenum.

 

[ransil]

Here is the other thread:
http://classicbroncos.com/forums/showthread.php?t=172770

I disagree with Steve \ Frank.

see post #2 for my $.02

 

[HoosierDaddy]

If "sealed" means they're not vented directly to the atmosphere, then they're sealed.

You stand corrected .... by yourself. ;D

I get your sealed vs ported arguement , will try to use the proper terminology (as I learn it ) from now on.

Will edit previous post.

 

[Ourobos]

Run it like Ford intended, EFI valve cover with NON-METERED air in the line from the throttle body to said valve cover. You CAN run it without, if you delete the PCV and run a breather on both valve covers, this is often done with supercharged cars, but is more liable to have blow by issues too.