EFI guys, BAP sensor questions.

[88 Fox GT]

I just got my barometric pressure sensor today. I see there is what looks like a nipple for a vacuum line or something similar too hook onto. Is this correct? If so, where does it go to?
Does the mounting location of the BAP sensor make a difference? Can it be mounted straight up and down on the firewall anywhere? Anyone have pictures of theirs? Thanks.

 

[88 Fox GT]

Ok, nevermind. I found out it does need to hook to a vacuum line on the intake manifold. So, I guess I need to turn this topic into something about vacuum.

As of right now, it looks like the only things I need to hook up for vacuum are the PCV, fuel pressure regulaor, and the BAP sensor. I'm not using the EGR or any other emissions stuff, so basically these are the only things that need hooked up. How about you other guys?

Also, I don't know if all intakes have this or what, but my TFS lower intake has a large circle on the back of it where a vacuum line hooks into. It's a pretty big hole, probably 1" in diameter. Where would this line run to?

 

[Ronstang]

BAP stands for Barometric Absolute Pressure. It does not hook to a source of vacuum. That port is designed to sample the air pressure and DOES NOT HOOK TO A VACUUM SOURCE. I'm not sure who told you this but they are misinformed.

 

[88 Fox GT]

Here is a quote from the Ford Fuel Injection page.
"The Barometric Pressure (BP) sensor operates as a piezoelectric (pressure-sensing) disc. However, rather than generating a voltage, its output is a frequency change. The sensor changes frequency relative to intake manifold vacuum. The sensor frequency increases as vacuum increases. The BP sensor is used to sense the changes in barometric pressure, allowing the PCM to sense the altitude at which the vehicle is operating. Its signal affects air/fuel ratio, spark and EGR for altitude compensation."
http://fordfuelinjection.com/bp.html

Are you saying a BAP (barometric absolute pressure) sensor and a BP (barometric pressure) sensor are two different types?

I thought they were all the same.

 

[Fostang]

The BAP and MAP are the same sensor just that one is hooked to the manifold through a vacuum hose and the other is vented to the atmosphere, Mass air cars use a BAP and a MAP is for Speed density set ups, you can use which ever on either set up......and thats my final answer.


Since you are using a Mass Air set up well that means it needs to vented.

 

[Ronstang]

The description of how it changes freq in relation to manifold vacuum is the description of how a MAP (manifold absolute pressure) sensor works...the rest sounds like it is talking about the BAP. Just don't hook up the vacuum to it....trust me and Fostang.

 

[mustangracer]

In fact, the BAP sensor on my swap has a fitting over the vacuum connection to keep anyone from accidentally attaching a hose to it...

So to third it, NO connection to manifold vacuum for MAss Air setups