Pressure and vacuum transducer testing

[BRIAN617]

Yes VE is Volumetric Efficiency, air in air out. But what are you using to test VE? Ford tool?

[Steve6911]

As Brian said VE is Volumetric Efficiency, I use it on almost every Driveablity issue, helps rule out a lot of things. First time I am using this one, I mis-labled the vehicle (2005 when its a 1997) but the reason it has no effect on the readings is that entering the vehicle is just a records keeping thing. As long as the "inputs" are correct which they were the tool will give the correct reading. I matched it up against the calculator I have been using and they are very close. This is from the same guy as the overlay program and its free.

https://www.topwindata.com/windowsap...or/565156.html

[Witsend]

Very cool programs , but Since it is a Ford Explorer/ Mercury Mountainer with a DPFE sensor couldn't you also have just plug the EGR valve vaccum tube, Pull the hoses off the DPFE sensor and feel the one that has the best back pressure puttering out the hoses and connect your pressure transducer directly to that hose and pinch off the other one to confirm you do indeed have 5psi exhaust back pressure? If relative compression check looked good, is pulling a sparkplug and going in cylinder testing easier than popping the hoses off a DPFE sensor ? A lot of times those newer Plastic DPFE sensors are already going into melt down mode when Ford's start to let you know you got an exhaust restriction issue too, still could be possible the pre cats could be more restricted for the cylinders on the opposite bank though

[Witsend]

Scanner Danner Exhaust Back pressure testing a Ford from the DPFE feed tube with a old school vacuum/ pressure gauge.

https://www.youtube.com/watch?v=JIU8j4YBZxw

I'm not sure what the range of pressure difference from one hose to the other hose that a DPFE sensor is capable of measuring before it change from 1volt base same pressure on each hose (no EGR flow) to reaching nearly 5 volts (VREF)? if you disconnect and plug the smaller DPFE hose and leave the small hose port of the sensor open to atmosphere and the larger hose still attached to the sensor then the sensor should show the voltage increase that is the difference between 1 volt at atmospheric pressure and the higher voltage in proportion to the higher exhaust pressure. Figure out what voltage the DPFE sensor reads at 2psi with a hand pump , and any voltage higher than that running with the smaller DPFE hose off the sensor and plugged (and the egr valve vacuum plugged) and you have an idea. If your over that voltage you got applying 2psi to the sensor with hand pump, you have over 2psi back pressure.

[Dr Dave]

How can I get the overlay ?Will it go on my zues? I have a engine in diagnosis i printed and drew lines with a ruler. How crazy lol pay 30k for my zues if I just do my payment and the laptop scopes are kicking its ***.there no possible way to diagnos s a cylinder pressure pattern on the verus,zue s without a proper layout.Sorry I goal was to find a way today hopefully you can guide me

[Steve6911]

Go to this post

http://productforum.autorepairdata.c...ad.php?t=12970

The first post in that thread has the link to the free download. It will only work on Windows 10 machines so you will have to copy the file over to a Windows 10 PC. If you don't have it already download ShopStream Connect, it will make it much easier.


Steve

[Mechatronics Engineer]

Why can't Shop Stream Connect have horizontal rulers as well as vertical rulers, followed by a legend!

[crackerclicker]

Originally Posted by Mechatronics Engineer

Why can't Shop Stream Connect have horizontal rulers as well as vertical rulers, followed by a legend!

Ask Bernie Thompson & Neal Pederson.

[Witsend]

Waekon Industries 48265 Pressure Pro PC, Automotive Scanner looks pretty multi faceted for a very reasonable price. I'm not sure how well the pressure transducer holds up, whether a sample rate of 1000 samples per second give enough detail a scope can, or any trigger can be set , but it sure looks like a pretty versatile PC program. Software might not support Windows 10 ,so may need to run it off an older Windows 7 or 8 PC.
You can search it on you tube and watch a company demonstration video , but didn't see any techs videos using and reviewing the tool and saying whether it works well or not

[Steve6911]

Here is a fairly new Video that goes into dept on the topic of this thread. It is not on a Snap-on Scope, but it all can be done on one. The Video is almost 3 1/2 hours but well worth watching.

https://youtu.be/CEiAN-VTDoY