Question for Paul

I had used a GM fuel tank pressure sensor to make a low pressure transducer. I have seen you do this in one of your videos a while ago where you tested a 4 cylinder Honda. I have yet to actually test this on a vehicle. I am wondering if this would work on a 6 or 8 cyl vehicle. I am also curious if you would share the scope settings you might use with this test.

A few things, that test that I showed is only valuable when you have a pressure regulator with a vacuum hose on top of it. As far as scope settings I don't remember but I believe that I used the scope set to AC couple. I think it's in the video but I don't have the link offhand and I don't remember which channel it's on sorry

Went ahead and moved this thread to Diagnostic Tools and Techniques. Just because it doesn't really have anything to do with the book.

ScannerDanner wrote: A few things, that test that I showed is only valuable when you have a pressure regulator with a vacuum hose on top of it. As far as scope settings I don't remember but I believe that I used the scope set to AC couple. I think it's in the video but I don't have the link offhand and I don't remember which channel it's on sorry

Hey Paul , thanks for the response. I am aware that the regulator needs to have a vacuum supply to it for the test to work, but I am unsure if the test can be used on a v6 or 8 engine. I had attempted to use this test today on my 96 jeep 4.0. However I could not get a pattern on the scope. And this is an inline 6 obviously. I can apply pressure or vacuum to the tool and get a pattern to form on the scope that way. What am I doing wrong?

You might need to poke a small pin hole in your hose going to the sensor.

This is taken off my 4 cylinder Acura Integra at the fuel pressure regulator vacuum port and the fuel injector furthest away from the regulator unplugged. I have it set on ac coupling, 50 ms time base and looks like 500 mv scale. I haven't tried with a V type engine.