Logging Fuel Pressure

[We're on Boost]

I've been wanting to log fuel pressure lately, so I started poking around on the subject about a week ago. I would be logging with my ecu+.
I found out some worthwhile info by sending an email to Prosport gauges and would like to pass it on, here it is:

Me: I want to buy an electric fuel pressure gage with a sender that puts out a signal I could log on one of the 0 to 5 volt analog inputs in my logger. Will the prosport electric fuel pressure gage sender give me a logable signal?

Prosport: You are going to have to use the premium series Fuel Pressure gauge as that has a 0-3v output signal that you can tap into.

Me: Do you mean I would tap into the green wire that goes to the sender? Or is there an actual port on the back of the gage that is made to be an analog output to a logger?

Prosport: You would have to tap into it, no normal output signal o the gauge.

Me: I can do that, no problem. Wouldn’t I be able to do the same thing with the less expensive gages though, I mean the “performance series” gages?

Prosport: no, because that sender on the performance series reads Ohms.

Me: Ok, that makes sense. Thanks!


So there you have it, one possible way to log fuel pressure. You would prefer the input on your logger to be a high impedence input so it doesn't throw off the reading to your gauge. Logging just plain old voltage doesn't tell you what the fuel pressure is directly. So before I install the gage on the car I will set it up on the bench with a fitting to an air compressor and read the voltage at several different air pressures. That will be my "calibration" table to convert volts to pressure. The "premium" gage with sender is about a hundred bucks.
BTW what got me thinking about this is a problem with a lean condition under load ever since installing my Walbro. I'm thinking the problem is with the Walbro install. So I might just do that different to see if it "fixes" the problem. Still, I've always thought it would be nice to be able to log fuel pressure, even before this problem happened.

Would appreciate comments if anybody has tried this or done it a different way!

Gary

[Hal]

Auto Meter

This is the sender I use with ECMLink

[We're on Boost]

Originally Posted by Hal

Auto Meter

This is the sender I use with ECMLink

That looks good.
Can you use this w/o the gauge? Or does the gauge have to be hooked up for it to work?
Does ECM Link convert the signal to psi for you, or does it just log volts?

Gary

[Hal]

You don't need th gauge, and ECMLink does indeed convert to signal to PSI.

[We're on Boost]

Originally Posted by Hal

You don't need th gauge, and ECMLink does indeed convert to signal to PSI.

I'm looking at the autometer install instructions for a fuel gauge. Looks like there are 3 wires to the sender but they don't say which wire is which.
Is it right that there are 3 wires to the sender? Are they +12v, ground, and the 3rd wire would go directly to the input on your link?
Are there better instructions somewhere that are just for the sender?

[this_tsi_8urV8]

Where would such a thing be hooked up to?

[We're on Boost]

Originally Posted by this_tsi_8urV8

Where would such a thing be hooked up to?

Well the 1/8" pipe threads will screw right into pretty much any aftermarket fuel pressure regulator gauge port. But if you are talking about the electrical end of it and if you are talking about DSMLink, I don't have a clue because I don't know anything about the hardware aspect of DSMLink. All I know is it is listed as a loggable parameter ( AMtrFuelPress ) here:
dsmlinkloggableparams [ECMTuning - wiki]
If you have a hardware logger like me (ecu plus) then you would have some inputs that are made for taking a 0 to 5 volt input, hopefully with a drop-down list of senders that it can translate from volts to the appropriate unit like psi. I've got one input where you can set up your own translater function, as long as it is linear. You key in the 2 endpoints of the line and it figures out everything in-between

By the way, Deftracing.com got some more info for me on the Prosport fuel pressure sender (the "premium" series one). They gave me a table of numbers for translation from volts to psi:

0.5v=14.5 psi
1.0v=29.0psi
1.5v=43.5psi
2.0v=58.0psi
2.5v=72.5psi
3.0v=87.0psi
3.5v=101.5psi
4.0v=116.0psi
4.5v=130.5psi
5.0v=145.0psi

As you can see, this is a linear function all the way through.
This Prosport sender is available by itself without the gage or any install kit for about $34. The sender with gauge and wire harness is only about $100. The autometer sender is $100 all by itself.

Gary