I am putting together a fuel pressure gauge using an unknown sender with no markings, an Innovate LMA-3 and XD-16 gauge. The innovate stuff is pretty slick and works. I have some serious questions about the sender and am wondering if I am doing something wrong.

While I dont know anything about the sender, I do know that it is a 5V unit. Most, if not all, 5V senders use a range from about 0.5V to 4.5V output to indicate pressure. The "quantity" of pressure is dictated by the limits of the unit. Typically you see 1 bar, 3 bar, 5 bar fuel pressure senders, but there are many, many more that can measure from very small amounts to very high psi (thousands.)

I hooked up my sender to my LMA-3 and then attached a hose to the input side and hooked the hose to a tire inflation thingy with a known accurate gauge. To calibrate the sender, I then put the sender under pressure and recorded the voltage in steps of 10 psi.

Unfortunately, the sender stopped sending increased voltage after about 1.4V (about 45 psi.) At the time, I interpreted this to mean that the sender was a 3 bar unit and useless to me as I need to measure pressures over 60 psi.

But on reflection, I think that maybe something is wrong. I will say that the LMA-3 will measure voltage up to 4.95V as I checked. So it is able to read higher than 1.4V. Might there be something I am doing wrong that is clamping the voltage to 1.4V? Is the sender bad?

Anybody got a sender of which they would like to be rid?

 

???

 

There is only a stamped "1" on the "Nut" part of the sensor. Wait one and I will go take a pic.

 

Well, now that you mention it there are markings on the wire. Unfortunately, they seem to just describe the wire.

Sez "BELDEN-M 8444 CMG 4C22 (UL) E108998 OR AWM 2576 OR C(UL) CMG 2007 1315 500 0091508 FEET"

 

Thank you for looking. I have some options if I cant figure out if this one is broke or has too small a range. Bro-in-law has another sensor laying around and we can test it to see if it has a broad enough range.

I also found a guy, named Bill Jones, that buys sensors surplus and sells them purty cheap. Has hundreds. Only issue is that he only takes cash. THat is that green paper stuff with the old dead guys picture on it. Not Paypal, not google checkout. Nor checks. Cash. And he lives in UT. Guess I will be breaking a federal law soon, shipping cash through the mail.

Then again, I can always break down and just pay the $100 and buy a sensor from Autometer or Digikey (Digikey has an AWESOME search function!)

Anybody else with some info, I would greatly appretiate it.