How do I fix inaccurate fuel gauge?
05-17-2014, 10:04 AM
#1
How do I fix inaccurate fuel gauge? Back in 2010, I had a friend install a Racetronix fuel pump kit for the LS3 motor in my '98 Z28. On the immediate test drive following the install, I notice the fuel gauge reads empty and I barely manage to get to a gas station, but it only took like 10 gallons to fillup. So we figure the sender arm was some how bent during installation. Since it was such a big PITA to drop the tank, I put it off. When I found out there were very few stock sending arms left in the nation, I ordered one and it sat in storage another 3 years until a few weeks ago when I took it to the dealer to fix the fuel gauge.
However, they wrote the ticket up as 'replace fuel sender, customers part' and not a diagnostic, so they don't apear to be willing to warranty anything after I paid $500 in labor. The Tech 2 is reporting 12.6g remaining on a 15.5g capacity when the tank is full. I rarely let it get below an 1/8th tank because I don't want to risk being stranded. Factory behavior was below E when truly empty and above F when truly full.
Would there be a workaround process to recalibrate the factory fuel gauge back to stock behavior using the fuel system tables in the PCM? If yes, can someone please provide the detailed steps? Thanks!
However, they wrote the ticket up as 'replace fuel sender, customers part' and not a diagnostic, so they don't apear to be willing to warranty anything after I paid $500 in labor. The Tech 2 is reporting 12.6g remaining on a 15.5g capacity when the tank is full. I rarely let it get below an 1/8th tank because I don't want to risk being stranded. Factory behavior was below E when truly empty and above F when truly full.
Would there be a workaround process to recalibrate the factory fuel gauge back to stock behavior using the fuel system tables in the PCM? If yes, can someone please provide the detailed steps? Thanks!
05-21-2014, 03:36 PM
#3
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I've seen the tables but never messed. I think I'd try and find
the raw reading PID first, get the tank empty and then add a
couple of (calibrated) gallons at a time so you know what the
raw reading is at 1/8, 1/4, ... 1/1 and then you should be able
to reprofile that table.
But I have no good idea what the PID for that index (raw) value
is called, or whether it's even an available quantity in the scan
tool.
the raw reading PID first, get the tank empty and then add a
couple of (calibrated) gallons at a time so you know what the
raw reading is at 1/8, 1/4, ... 1/1 and then you should be able
to reprofile that table.
But I have no good idea what the PID for that index (raw) value
is called, or whether it's even an available quantity in the scan
tool.
05-21-2014, 03:38 PM
#4
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If he installed the racetronix kit did he Repin the level sensor ?? They go into the new connector. I almost missed that part when I installed mine last week.
But I don't know if the tech 2 would pick that up if it wasn't. If you had access to a new one you can also ohm out the float at full and empty and then figure half and quarter from there.
But I don't know if the tech 2 would pick that up if it wasn't. If you had access to a new one you can also ohm out the float at full and empty and then figure half and quarter from there.
05-21-2014, 04:39 PM
#5
TECH Enthusiast
It can be done through the PCM but the question is which one are you using? It sounds like you are using the gauge with the 98 wiring through the PCM. If so it can be programmed to correct the gauge.
05-22-2014, 08:50 AM
#6
I'm using the stock 1998 instrument cluster, PCM and engine harness. I provided the color installation instructions to the installer, I do not specifically know if he re-pinned the level sensor. I would have to dig out those instructions. Although going over the online Racetronix F98 installation guide I think you're referring to steps 17-20 and I'm pretty sure that was done.