j curtiss

I have a '99 FRC with the dreaded gas gage problem. I've tried and had limited success with the Techron treatment. I'm now feed-up with this problem and ready to fix it once and for all.

So I used the search function in this forum to find the "cure" and came away confused. Some say it's a reprograming problem, others say to change the sending unit, while others still swear by Techron. And to add to the confusion, there seems to be a "sending" unit and a "sensor" unit?

My plan is to change the rehostat device (sending or sensor?) in the tank. I assume it's installed in the RH tank and it can be removed without first removing the tank?

Any clarification or advice on how to fix this goofy gas gage problem permanently will be greatly appreciated.

David426

There are 2 sending units, one in each tank.. Once they cake up with too much sulfer terchron wont work

holterhouse

Had the problem in my 99 roadster (14000 mi) last summer.Dealer pulled tanks and replaced pumps for $1400.00.

9secondflat

you need to replace the sending units AND get the computer reprogramed...the problem is if you have a custom program...it will be errased after the computer is reprogramed by a gm dealer...there was a service bulliten that explains the process..

9secondflat

if the dealer replaced "pumps" i would march back to that dealer...there is only one pump in the left tank....

j curtiss

Thank you for the responses. So there's a sending/sensor unit in each tank and I assume they both need to be replaced. Can these be replaced without first removing the gas tanks? Has anyone done this in a home garage?

I don't have any "custom" program of any sort, so I should be OK to reprogram. Where is the Service Bulletin that explains the process?

Much appreciated,

Jason

9secondflat

i had a hole in my gas tank and watched the replacement...in 99-02 c5s, there is a metal pan that is holding the tanks in place and also provides protection..i belive its 4-6 screws that hold it in place (2-3 minutes tops to remove) then (if not done disconnect battery), unclip the fuel line connections (if the tank is empty then this helps alot..if not you will have to drain the tank) next the sensor- is held in place with a few screws...it can be r&r'ed from start to finish in about an hour...my local shop did the right tank and replaced the sensor etc...start to finish in less then 3 hours...(could have been done in less time but the cross over hose took about 20 min to connect)..


here is a gm tsb...a later one has the memmo of reflashing upon completion of changing the sensors..

1997-2000: Service Bulletin: Inaccurate/Erratic Fuel Level Gauge Readings
Source: Chevrolet Dealer Service Bulletin
Number: 01-06-04-022
Subject: Inaccurate/Erratic Fuel Level Gauge Readings (Install New Sensor, Strainer and/or RH Fuel Sender Assembly)
Model Year: 1997-2000 Chevrolet Corvette
Condition
Some owners may comment about inaccurate/erratic fuel level gauge reading conditions such as those indicated below:
Fuel gage suddenly drops to E (empty) and CHECK GAGES message illuminates (DTC P1431 or P0461 set).
Fuel gage does not go to F (full) after filling fuel tank.
Vehicle runs out of fuel while the gage still indicates fuel is available.
Cause
The conditions indicated above may be the result of one or a combination of more than one of the causes indicated below:
Stuck or intermittent sticking of the sensor float arm.
Clogged/restricted R.H. fuel sender assembly jet pump.
R.H. jet pump unable to transfer fuel due to fuel vaporization resulting in bubble accumulation in the fuel strainer.
Correction
Inspect the Julian date codes located on the bar code labels attached to the R.H. and L.H. fuel level sender assembly cover plates as shown in the figure. If the R.H. sender date code is less/smaller than "01301", replace the complete assembly with a new fuel sender kit indicated below by model year. If the L.H. sender date code is less/smaller than "32791", replace the existing fuel sender sensor and strainer with those components contained in the applicable sensor and strainer kits shown below by model year.
To insure correct installation, follow the service procedure contained in the applicable Service Manual and the instructions contained in the service kits.
Parts Information
Part Number
Description
88896043
R.H. Fuel Sender Kit (1997-1999 M.Y.)
88895126
R.H. Fuel Sender Kit (2000 M.Y.)
88899034
Fuel Sensor Kit (1997-2000 M.Y.)
12458245
Fuel Strainer Kit (1997-1999 M.Y.)
12459862
Fuel Strainer Kit (2000 M.Y.)
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information

redrckt97

why would the PCM have to be re-programmed after fuel sender replacement??

9secondflat

in the most recent gm service tsb for c5's with irratic fuel gauge program, they say to reprogram the computer after installation...i was trying to find that tsb..(i have it, just cant locate it on my computer)..

j curtiss

So it sounds like the tank doesn't have to come out to replace the sending unit?

GM Parts Direct doesn't recognize the R.H. Fuel Sender Kit 88896043, but does show a part no. 88899034. I assume this p/n is for the L.H. sensor; so is there a part no. for the R.H. sender/sensor?

Thanks,

Jason

9secondflat

http://www.racetronix.com/Manuals/C5...%20Voltage.pdf

TPA Z06

BG-44K. From what I've read, it's the shizzle.....

ZeeOSix

The BG-44K is expensive, but I hear it works very well. Another alternative to try is Redline Fuel System Cleaner.

Armycop

Huh? You have an aftermarket fueling system? fuel pump in driver's side tank, fuel sending unit in pass. side tank; pump provides fuel to sending unit, "Venturi Effect" sends fuel back to the primary (drivers) tank via the sending unit. Both have a rheostat-type (long arm with a float) fuel level gauge on them. If you are getting fuel to the rails, then your fuel pump is working. If you are only getting 9-10 gals of fuel used per fill-up, then your sending unit (pass. side tank) is bongo.

ZeeOSix

David426 was right when he said thier is a fuel level sensor ("sensing unit") in each tank. If they are not reading "in sync" like the ECU thinks they should, then a DTC is set.

dmoore

Did you try Seafoam? That worked better for me then Techron did.