"Short Link Air Flow"

[robertc1024]

I don't know about the newest technologies, but when Ford switched from the SD/MAP (manifold air pressure) system to MAF, they also used a BAP (barometric air pressure) sensor to accomplish that. It looks identical to a MAP on my Mustang.

EDIT: This is what mine is:
http://www.latemodelrestoration.com/item/DY530/1989-93-Mustang-50L-Barometric-Air-Pressure-Sensor-Bap-Senso

I'm not sure how the BAP Sensor "provides manifold vacuum readings to the PCM" when it has no vacuum line. Seems like a bad description.

Sorry DG, hang in there.

That is what I'm talking about. A BAP sensor needs no vacuum line because it's just reading the barometric pressure. In the fall/winter when cold fronts come through, it can change the barometric pressure >0.5 psi. If you engine doesn't compensate for it, it's a free 0.5 psi supercharger.

I've seen systems for aircraft where you can add a turbo and all it does is maintain atmospheric pressure at ground level when you are flying at 10,000 feet. Your engine doesn't get FAA turbo certified (or whatever it is) because it's operating in an environment as if you were on the ground. At 10,000 feet, that would be ~4.6 pounds of boost.

 

[James86]

The thing that interests me is that Ford puts a temp sensor about mid way between the airbox and the throttle body, but then - on my 3.0 anyways - runs COOLANT LINES branched form the heater lines to the upper intake plenum just after the TB, so I wonder how much of a temp difference between what the temp sensor sees and the actual air temp inside the intake. I've also read around that not all 3.0's had it and some people actually disconnect it for a cooler intake charge... I haven't dicked with it but it is something that kinda makes me curious. Could it be an attempt to COOL the intake slightly since it's hooked to the intake about where the EGR valve is?

 

[shane96ranger]

The thing that interests me is that Ford puts a temp sensor about mid way between the airbox and the throttle body, but then - on my 3.0 anyways - runs COOLANT LINES branched form the heater lines to the upper intake plenum just after the TB, so I wonder how much of a temp difference between what the temp sensor sees and the actual air temp inside the intake. I've also read around that not all 3.0's had it and some people actually disconnect it for a cooler intake charge... I haven't dicked with it but it is something that kinda makes me curious. Could it be an attempt to COOL the intake slightly since it's hooked to the intake about where the EGR valve is?

I'm not as familiar with the 3.0 Vulcan as I'd like to be. By what you're saying, if I am understanding correctly, you have a temp sensor IN the throttle body? For water or air? The coolant lines are there to regulate the temperature of the EGR. The EGR plate on my Mustang was leaking coolant into the intake, so I no longer use it. I didn't notice any difference.

The one thing that needs to be mentioned, is Ford programmed the ECU to expect certain parameters from their sensors. Messing with locations, etc. could make more issues than it helps. The most critical sensor on your system is the MAF. I actually relocated my IAT sensor on my Mustang from the intake manifold to the intake pipe because the manifold I put on it had no boss for it. It still runs the same.

You could play with locations a bit, just don't cut the piss out of something you might need later if the results are not satisfactory. Been there - done that.

Sent while I should be doing something else

 

[Mac]

On the later Explorer 5.0L's, they moved the IAT sensor right into the MAF. Things are always changing. Don't know ablut the newer ones.
Dave

 

[AllanD]

Sorry DG, hang in there.

That is what I'm talking about. A BAP sensor needs no vacuum line because it's just reading the barometric pressure. In the fall/winter when cold fronts come through, it can change the barometric pressure >0.5 psi. If you engine doesn't compensate for it, it's a free 0.5 psi supercharger.

I've seen systems for aircraft where you can add a turbo and all it does is maintain atmospheric pressure at ground level when you are flying at 10,000 feet. Your engine doesn't get FAA turbo certified (or whatever it is) because it's operating in an environment as if you were on the ground. At 10,000 feet, that would be ~4.6 pounds of boost.

That is called "Altitude compensated"

Ford actually kept using a MAP sensor on the first few years of the 4.0 before they determined that they really didn't need it.

The Ford BAP sensor was used on the Turbocharged 2.3 and if you know the programming architecture of the 2.3Turbo engine management you'd also know that the system "peeks" at a reading from that sensor as the key is turned through "run" on the way to "start" and it thereafter IGNORES the BAP sensor until the key is cycled.

Thus some people discovered that driving a 2.3EFI-Turbo ford vehicle through a LARGE altitude change would get some flakey engine behavior that would disappear of the key was cycled to off momentarily

 

[James86]

I'm not as familiar with the 3.0 Vulcan as I'd like to be. By what you're saying, if I am understanding correctly, you have a temp sensor IN the throttle body? For water or air? The coolant lines are there to regulate the temperature of the EGR. The EGR plate on my Mustang was leaking coolant into the intake, so I no longer use it. I didn't notice any difference.

That's sorta what I figured. Like I said, the temp sensor is actually in the pipe running from the airbox to the throttle body, but there are coolant lined to the UPPER intake plenum itself, not the EGR, but it is about where the EGR mounts, so I suppose it could be used for cooling...

ED: Yes, I know I changed the hose, but everything is otherwise in it's stock locations:

My friend's 1998 3.0 has the same lines, but I never noticed it on other 3.0's like the multiple Taurus's or Tempo's I've seen....

 

[press 1 for english]

huh?

I agree!