I am starting a new thread rather than change the direction of the digital fuel gauge thread. We recently noticed that our fuel gauge, which used a centroid capacitance type sender, is not reading accurately. The gauge said 3/8, which meant I should take 100 gallons, but it only took 70. On our return from a 200 mile trip, it showed 1/2 tank, which meant i had a fuel leak or the new engine was drinking a whole lot more fuel than our old one. When we got home, I looked into the tank and found that it is at least 3/4 full.
I emailed Joel at Centroid Products, explaining what was happening. this is the reply I received. Jack
Jack:
1. 5/5/09: SUMMARY FOR MY RECORDS
Jack's MCI motorhome fuel reading was originally accurate, but recently he had a 3/8 reading (=64g remaining of of 170g; 106g to fill) and was only able to put in 70g. But the needle did read F when he filled. Now the gauge is showing 1/2 but looking into the tank it appears that 3/4 or higher would be a more accurate reading. Formerly, he would stop at a 1/4 reading (43g remaining; 128g to fill) and put in 125g. Yes, this is correct.
5/5/09: JACK REPORTS:
--Diesel fuel
--He hasn't played with the adjustments between the good and bad readings
--He cant recall if the old Full reading was on the Full mark or above it.
2. ABOVE FULL
I found out about a month ago (by having another customer make a measurement) that the modern ultra-low-sulfur diesel has less capacitance than standard diesel used to. My guess from your answers is that
--your current low readings are due to the ULSD
--your Full reading used to be above Full, if it is now on Full
You have a good situation in that it's easy for you to check how much fuel is in your tank. My suggestion is that you run your tank down to 1/2 and use the Full adjustment to put the needle on 1/2. That should put your low readings back to what you were used to, and your Full reading back to what I believe will have been above Full. I haven't ever seen a sender come back where the middle readings had dropped but the needle still went to the same spot at Full, is what makes me conclude the above conclusions.
Joel
Jack,
It sounds just crazy enough to maybe be true!
I look forward to hearing the opinions of those more knowledgeable on these matters.
Cliff
side note: The generator situation may soon be resolved via your contact........
Quote from: FloridaCliff on May 06, 2009, 06:09:44 AM
Jack,
It sounds just crazy enough to maybe be true!
I look forward to hearing the opinions of those more knowledgeable on these matters.
Cliff
side note: The generator situation may soon be resolved via your contact........
Great, hope it works out. Jack