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Ugh Fuel Gauge reading way past empty when full?

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Old 04-01-2010, 12:38 AM
  #1  
01MGGT
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Default Ugh Fuel Gauge reading way past empty when full?

Ok so I finally got my damn Focus pump and PPRV delete done. While we had the basket out we pulled a hair to far and pulled out that little tiny wire that is soldered to the white board inside the metal plate on the front of the basket. I understand this is the fuel level sending unit. We soldered it back on and it seems well connected. I continued to reattach the float arm and put the hat back on. With the car still on jacks and the tank down we hooked the positive back up to battery and turned on they key.

Car started but gas gauge read way past empty. Pulled hat back off and manually moved the float arm up and down a few times and it ended up reading somethign finally but don't remember what. Now for the past day after putting the tank up it has read anywhere from between 1/2 and a 1/4 up to right before I got gas it was reading almost full. Filled her up which took like 9.2 gallons and now all the way home my gauge was on flat zero with LFL on. I am lost. Today I ran to the store and it was reading above 1/4 when I went in and I parked where the rear of the car sloped down hill a bit and came out with it still running and found it to be at way past empty and after backing up a tad it was back up again! I can't think of anything else that could have gotten broken! I don't want to drop my tank a third time
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Old 04-01-2010, 09:15 AM
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01MGGT
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sheesh a new sender is 124 bucks
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Old 04-01-2010, 11:15 AM
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01MGGT
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Ok so, before I got gas yesterday iw as reading almost full. Put gas in and it went to all the way below empty. Reset ecu and stuff and no change. Started car this morning with the *** end sloped slightly down hill and it read full. Stopped at store on the way to work and left it running. Came out and parked on basically same type of slope it was pagged past empty with light on again. Get to work and park it ona tiny slope but mostly flat. Turn off engine and turn key back on multiple times and it read full again! I am stating to think it's a bad ground. Which if I remember correctly it mounts to the front side of the little metal box thingy right? It has to be ground. That would explain why it would read absolutely nothing is ti has no ground to make a good resistance reading right? I did remove that ground to get the metal thing off to resolder the other wire so that must be my problem. I reinstalled it with the tiny screw back on outside of the metal cage at bottom of the basket. Anyone got a pic of how this should look so I can check it when I drop tank again?
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Old 04-01-2010, 11:32 AM
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budders
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someone should help him, lol. and btw i have no clue, but check your grounds would be a start

Last edited by budders; 04-01-2010 at 11:38 AM.
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Old 04-01-2010, 11:48 AM
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01MGGT
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thanks for at least replying budders lol. I figure at least cliffy should have some advice. It was working fine before I removed the sender unit to resolder the wire. Ground has to be it. Some people even said the tank straps bolts not being all the way tight can cause ground problems. The car runs liek a champ now and I am still going to have to drop the tank a third time! FML! lol
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Old 04-01-2010, 01:13 PM
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ok an update with some info that may help. First off I am using the instrument cluster diagnostic info found at these two links:
Mustangworld HEC Instrument Cluster Diagnostics
HEC Diagnostic Mode

With the car on I am seeing the gauge randomly at either full or way past empty (I currently have a full tank of fuel) and the cluster diagnostic is showing DTC code 9202 Fuel Sender Open Circuit. It's also showing 5284 oil pressure switch failure but that gauge seems to work fine.

While driving if I set the cluster to the FUEL readout it stays pretty solid at 255 but will fluctuate between that and no lower than about 220 I would say. According to that link 255 = Open Send +/- 0 and 232= Full Stop +/- 0 and 215= Full Mark +/- 10

I should add that no matter what my fuel gauge is reading (full or all the way empty) this reading pretty much stays the same!
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Old 04-01-2010, 06:20 PM
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i wish i knew something that would help you, cant believe nobody chimed in with something to help you yet, sorry man =/
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Old 04-01-2010, 07:41 PM
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vanquish
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When I first started reading this thread I thought your fuel float was just bent below the pickup on the pump so you were reading more than you have.

This happened to me so I bent the float slightly above the pump pickups so I would always read less gas than I had.

Your problem sounds different though but it may help to do what I mentioned. Make sure when you put the fuel hat back in the tank you don't accidently bend it to ruin the way you set it.
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Old 04-01-2010, 10:59 PM
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01MGGT
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I am starting to think its an electrical problem. Wouldn't an open circuit be a grounding issue?
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Old 05-14-2013, 02:08 PM
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Did you ever find a resolution to this? I'm running into what looks like the same issue. Just replaced the floats and sending unit and still no go.

**edit**
Nevermind, we resolved the issue, it was a wiring issue, I think it was the float sensor wires between the 2 sides of the saddle were crossed.

Last edited by danzcool; 05-15-2013 at 10:51 AM.
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