Fuel sending unit flush out.
Thread Starter
Racer
Joined: Mar 2011
Posts: 337
Likes: 1
From: Mechanicsville Md
Fuel sending unit flush out.
My fuel gage keeps going to zero after about 50 minutes of driving. I reset it via the DIC and have continued to use techtron fuel additive with no improvement. I read that the system constantly compares fuel levels in right and left tanks and when the difference gets too large the gauge will zero out. I'm wondering if I can disconnect the right tank jett pump return line and blow it out without removing the sending unit from the tank? If I drive the car to 1/4 tank I'll run out of gas and still have gas in the right tank. Any help would be greatly appreciated. Thanks.
Pro
Joined: Dec 2010
Posts: 643
Likes: 0
From: Pleasant valley New york
I'm having the same problem and either after sharp pothole jar or really sharp turn it pops back up again. I just posted a similar question. Will be interesting to see what the responses are. It's really annoying !!!
Advanced
Joined: Apr 2010
Posts: 98
Likes: 2
Thread Starter
Racer
Joined: Mar 2011
Posts: 337
Likes: 1
From: Mechanicsville Md
If the jet pump gets clogged it does not transfer fuel back to the left tank. If there's a disparity greater than 1 to 2 gals between left and right tanks the gage goes south. I want to know how to take compressed air and blow the line(s) out without removing the sending unit. If this doens't work than replacing the sending units are the only remaining maintenance that needs to take place. If I can blow the debrie out of the jet pump orfice without removing all the gas and sending units I can keep it working until I get the sending units delivered. Thanks to all.
Pro
Joined: Oct 2006
Posts: 515
Likes: 133
Probably won't work. The nozzle internal to the jet pump has to be really small (guessing .020 or .030 or so). If you blow into the motive inlet, you are likely to just wedge whatever it is in tighter. If you blow into the outlet, you won't build up any pressure because the air will go out the tank port.
I have read that some people have been successful in remving the pump and unclogging the nozzle with a piece of wire.
There is some sort of pressure regulator in the motive line. I suppose it could be clogged too, although I haven't read anything about this.
In spite of ther above it could be worth a try.
I have read that some people have been successful in remving the pump and unclogging the nozzle with a piece of wire.
There is some sort of pressure regulator in the motive line. I suppose it could be clogged too, although I haven't read anything about this.
In spite of ther above it could be worth a try.
Melting Slicks
Joined: Jul 2000
Posts: 2,107
Likes: 14
From: Lancaster PA
If your jet pump is clogged, replacing the sending units is unnecessary.
I just went through this with my 02 Z06. I just pulled the right tank pump assembly and could not blow through it. I probed it with a spray gun tip cleaner which is a piece of thin straight wire.
I also replace the small filter that is in the right tank.
It has been working great ever since with no gauge issues or running out of fuel.
It is not that hard to do as the sending unit comes out of the back of the tank so you don't have to drop it.
I did test the jet pump after the clean out by disconnecting the return line to the left tank and running fuel pump by jumping the relay.
I just went through this with my 02 Z06. I just pulled the right tank pump assembly and could not blow through it. I probed it with a spray gun tip cleaner which is a piece of thin straight wire.
I also replace the small filter that is in the right tank.
It has been working great ever since with no gauge issues or running out of fuel.
It is not that hard to do as the sending unit comes out of the back of the tank so you don't have to drop it.
I did test the jet pump after the clean out by disconnecting the return line to the left tank and running fuel pump by jumping the relay.
Thread Starter
Racer
Joined: Mar 2011
Posts: 337
Likes: 1
From: Mechanicsville Md
Thanks for the feed back. I heard about this but needed to know procedures. How did you empty the right tank? Can you identify the lines on the tank. Top one bottom one? I sure do appreciate it. Thanks again.
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Melting Slicks
Joined: Jul 2000
Posts: 2,107
Likes: 14
From: Lancaster PA
I suggest doing this outside or a well ventilated area.
You must get the rear of the car up in the air and pull the right rear wheel.
Remove the inner wheel house plastic shield.
Remove the rear aluminum tank shield to expose the rear of the tank.
Have some 5 gallon buckets ready and disconnect the lines and let it
run out into the bucket.
When it stops running out remove the screws to the sending unit assembly and remove.
You will have to get some mini fuel line clamps to replace the crimped on ones when you disconnect the hose to the jet pump.
I could not see through the jet pump or blow through it until I probed it with a small wire.
I then sprayed some 2+2 cleaner through it to make sure it was open.
Don't over tighten the screws when putting it back together.
Good Luck,
Craig
You must get the rear of the car up in the air and pull the right rear wheel.
Remove the inner wheel house plastic shield.
Remove the rear aluminum tank shield to expose the rear of the tank.
Have some 5 gallon buckets ready and disconnect the lines and let it
run out into the bucket.
When it stops running out remove the screws to the sending unit assembly and remove.
You will have to get some mini fuel line clamps to replace the crimped on ones when you disconnect the hose to the jet pump.
I could not see through the jet pump or blow through it until I probed it with a small wire.
I then sprayed some 2+2 cleaner through it to make sure it was open.
Don't over tighten the screws when putting it back together.
Good Luck,
Craig
Melting Slicks
Joined: May 2008
Posts: 2,606
Likes: 355
From: Rochester New York
Just FYI, if your corvette has a fuel return line you can use it to drain the fuel and avoid making a mess. Disconnect the return line, press a rubber hose onto the fuel rail where the return line was, route rubber hose into the container you wish to fill with fuel, start the engine and allow the fuel to return into your container. A full take would take 20 mins or so.
Tech Contributor
Joined: Jan 2007
Posts: 19,454
Likes: 1,160
From: Dyer, IN
Just FYI, if your corvette has a fuel return line you can use it to drain the fuel and avoid making a mess. Disconnect the return line, press a rubber hose onto the fuel rail where the return line was, route rubber hose into the container you wish to fill with fuel, start the engine and allow the fuel to return into your container. A full take would take 20 mins or so.
Thread Starter
Racer
Joined: Mar 2011
Posts: 337
Likes: 1
From: Mechanicsville Md
Thanks. I will look for a return line/rail. If not I'm hoping that I can remove the return line from the right tank and drain it from there. I've read that you can jumper the fuel pump relay and empty it that way too. Can't seem to find that link. Any help?
Melting Slicks
Joined: Jul 2000
Posts: 2,107
Likes: 14
From: Lancaster PA
If your jet pump is clogged then running the fuel pump will only empty the left tank which is causing your running out of fuel problem.
Just disconnect the line from the right tank and let it run into the buckets.
It won't take long and if your careful it won't make a mess.
Don't do it where there are any pilot lights etc. nearby.
Just disconnect the line from the right tank and let it run into the buckets.
It won't take long and if your careful it won't make a mess.
Don't do it where there are any pilot lights etc. nearby.