Fuel not filling to max

[kujiwara]

Ever since I bough my Jetta I've never seen the gas gauge go to full 7/8 is max, and I run out of gas once and it stopped filling at 49L, I'm pretty sure that a mk4 has a 55L tank, can someone chime in about this? The fuel pump and level senders are brand new oem changed a few months ago and didn't change anything. The gauge should also be fine as tested with vagcom.

[BaggedGLI]

Re: Fuel not filling to max

Should be a 55L tank.

I know on Audi's you can adjust the level with Vagcom, not sure off the top of my head for the process with VW.

Did you fill until it clicked off then stop? Or did you let it click off a few more times?

[witchcraftz]

Re: Fuel not filling to max

You can adjust it with vagcom, I have one if you want to come over.


STEP 1 - CHECK THE INSTRUMENT CLUSTER FOR ANY INTERNAL ERRORS

1. Turn the car ignition on, but do not start it. Using the VAG-COM, go into the Instrument Cluster control module (-17-) and select OUTPUT TESTS (-03-).
2. Click on the START/NEXT button to initiate a sequence of tests. The first of these tests the sweep and calibration of the analog gauges. The needles for all four gauges (tach, speedo, coolant temp, fuel level) will drop to 0, sweep slowly all the way to their maximum, and then drop down to a calibration position. These positions are:
Tach - 3000 RPMs
Speedo - 62 MPH (100 KPH)
Coolant Temp - 190°F (90°C)
Fuel Level - 1/2 tank
The Bentley CD indicates that if any of these settings in incorrect, then there is an unrepairable error in the instrument cluster and it should be replaced. All of mine are good, except for the fuel level, which displays just under 1/2 tank. This is obviously part of the reason for my incorrect fuel reading, but I'm not going to pay for another cluster just to fix it. Instead, you can use the VAG-COM to fudge the displayed level.
3. Click the START/NEXT button to cycle through all of the remaining output tests. These tests will check the various warning lights, chimes and LCD displays in the cluster.
4. Keep clicking the START/NEXT button until END comes up, click it once more and then click EXIT to go back to the main menu for the Instrument Cluster control module.

STEP 2 - ADJUSTING THE DISPLAYED FUEL LEVEL
These steps are based on those given in the Bentley CD and are intended to be used after the fuel level sender has been replaced. The proper way to calibrate the fuel gauge to the new sender is to drain the fuel tank, add 7 liters (1.85 gal) of gas, which is the exact amount in the "reserve" tank, and then adjust the fuel gauge needle so that it coincides with the red "reserve" line on the fuel gauge. I wasn't about to go through this, so I filled up my tank and adjusted the needle so that it read full (or as close as I could get it). The VAG-COM allows you to adjust the position of the needle an amount equal to 2 liters of fuel in either direction (+/-) of it's normal factory setting. To do this, do the following:
1. Select ADAPTATION (-10-) on the main screen of the Instrument Cluster control module.
2. In the CHANNEL box, enter 30 and then click on READ. This will display the stored value for the fuel gauge calibration and normally should be 128. You may enter a value from 120 to 136. Each number corresponds to a 1 ohm adjustment of the fuel level sender output and corresponds to 1/4 of a liter. You can use the UP and DOWN buttons to adjust the number while you watch the gauge needle move. If you're doing it the proper way, then adjust the needle until it lines up perfectly with the red mark on the gauge. If you're doing it a different way, like I did, then adjust the needle until it sits where you want it to.
3. Click on SAVE. The new setting is now being used.
That's about it. If you mess something up and want to go back to the original setting, it's 128.
http://forums.vwvortex.com/showthread.php?3208286

[kujiwara]

Re: Fuel not filling to max

Should be a 55L tank.

I know on Audi's you can adjust the level with Vagcom, not sure off the top of my head for the process with VW.

Did you fill until it clicked off then stop? Or did you let it click off a few more times?

I've clicked it off a few times when the car ran dry one time so it should be somewhat close to 55 instead of only 49

[kujiwara]

Re: Fuel not filling to max

You can adjust it with vagcom, I have one if you want to come over.


STEP 1 - CHECK THE INSTRUMENT CLUSTER FOR ANY INTERNAL ERRORS

1. Turn the car ignition on, but do not start it. Using the VAG-COM, go into the Instrument Cluster control module (-17-) and select OUTPUT TESTS (-03-).
2. Click on the START/NEXT button to initiate a sequence of tests. The first of these tests the sweep and calibration of the analog gauges. The needles for all four gauges (tach, speedo, coolant temp, fuel level) will drop to 0, sweep slowly all the way to their maximum, and then drop down to a calibration position. These positions are:
Tach - 3000 RPMs
Speedo - 62 MPH (100 KPH)
Coolant Temp - 190°F (90°C)
Fuel Level - 1/2 tank
The Bentley CD indicates that if any of these settings in incorrect, then there is an unrepairable error in the instrument cluster and it should be replaced. All of mine are good, except for the fuel level, which displays just under 1/2 tank. This is obviously part of the reason for my incorrect fuel reading, but I'm not going to pay for another cluster just to fix it. Instead, you can use the VAG-COM to fudge the displayed level.
3. Click the START/NEXT button to cycle through all of the remaining output tests. These tests will check the various warning lights, chimes and LCD displays in the cluster.
4. Keep clicking the START/NEXT button until END comes up, click it once more and then click EXIT to go back to the main menu for the Instrument Cluster control module.

STEP 2 - ADJUSTING THE DISPLAYED FUEL LEVEL
These steps are based on those given in the Bentley CD and are intended to be used after the fuel level sender has been replaced. The proper way to calibrate the fuel gauge to the new sender is to drain the fuel tank, add 7 liters (1.85 gal) of gas, which is the exact amount in the "reserve" tank, and then adjust the fuel gauge needle so that it coincides with the red "reserve" line on the fuel gauge. I wasn't about to go through this, so I filled up my tank and adjusted the needle so that it read full (or as close as I could get it). The VAG-COM allows you to adjust the position of the needle an amount equal to 2 liters of fuel in either direction (+/-) of it's normal factory setting. To do this, do the following:
1. Select ADAPTATION (-10-) on the main screen of the Instrument Cluster control module.
2. In the CHANNEL box, enter 30 and then click on READ. This will display the stored value for the fuel gauge calibration and normally should be 128. You may enter a value from 120 to 136. Each number corresponds to a 1 ohm adjustment of the fuel level sender output and corresponds to 1/4 of a liter. You can use the UP and DOWN buttons to adjust the number while you watch the gauge needle move. If you're doing it the proper way, then adjust the needle until it lines up perfectly with the red mark on the gauge. If you're doing it a different way, like I did, then adjust the needle until it sits where you want it to.
3. Click on SAVE. The new setting is now being used.
That's about it. If you mess something up and want to go back to the original setting, it's 128.
http://forums.vwvortex.com/showthread.php?3208286

I've seen this and considered about it but right now is I don't think there's enough fuel going into the tank instead of the needle at the wrong place, I'll come over over the weekend if you're free

[Jester B]

Re: Fuel not filling to max

I agree that it sounds like a capacity issue, not a measuring/reading issue. Is your tank dented? Any chance a previous owner put rocks or something in it that is taking up volume?

[kujiwara]

Re: Fuel not filling to max

I agree that it sounds like a capacity issue, not a measuring/reading issue. Is your tank dented? Any chance a previous owner put rocks or something in it that is taking up volume?

Hmm i never thought of that, I'm sure there's no rocks that will take 5L of space in my tank but I'll check for dents.
I'm thinking it could be some sort of ventilation issue when filling up? I read up about it and saw the words "purge valve" and "carbon canister", will these two things affect this issue?

[MechEngg]

Re: Fuel not filling to max

How would dents or rocks in the tank cause a measurement issue? It doesn't measure the volume, it measures the liquid level (tangeable) and then calculates the % volume based on that. Any volume taken up by rocks on the bottom of the tank would not prevent the system from getting up to 100% full.

I'm thinking that your sender unit isn't calibrated correctly, even from stock i'm not sure that they come calibrated to work with your ECU. There is also ability for different revisions of sender units having slightly different range scales.

I've never been able to put over 50L in my tank, even when it was basically dry. It has always been 49.x liters. I definitely haven't been able to put a full 55L in it either, so your tank isn't honestly out that much.

My vehicle has had gas filling issues, i have to fill mine slowly or else it creates too much back pressure and shuts off the pump because the nozzle trips out. It has something to do with the purge valve or LDP it seems:
http://forums.vwvortex.com/showthrea...Fueling-Issues

[kujiwara]

Re: Fuel not filling to max

How would dents or rocks in the tank cause a measurement issue? It doesn't measure the volume, it measures the liquid level (tangeable) and then calculates the % volume based on that. Any volume taken up by rocks on the bottom of the tank would not prevent the system from getting up to 100% full.

I'm thinking that your sender unit isn't calibrated correctly, even from stock i'm not sure that they come calibrated to work with your ECU. There is also ability for different revisions of sender units having slightly different range scales.

I've never been able to put over 50L in my tank, even when it was basically dry. It has always been 49.x liters. I definitely haven't been able to put a full 55L in it either, so your tank isn't honestly out that much.

My vehicle has had gas filling issues, i have to fill mine slowly or else it creates too much back pressure and shuts off the pump because the nozzle trips out. It has something to do with the purge valve or LDP it seems:
http://forums.vwvortex.com/showthrea...Fueling-Issues

My old 03 2.8 gli always take over 50L but I never saw this blue car go over 50L even when it had the 1.8T. When I did the engine swap I did find out the fuel pump and tank is different on this 04(didn't change it), maybe our late model GLi has a smaller tank? Does your gauge go to max when you fill up?

[MechEngg]

Re: Fuel not filling to max

Should have the same size tank. My gauge goes up to max and works just fine

Also my old 2003 wolfsburg never took over 50L either....

[Geobmx4life]

Re: Fuel not filling to max

Have you pushed the vent button on the left side of your tank fill port? Thastll Hel you get a few more liters in by ventimg, but as for your guage....try Witchcrafts vag-com idea.

[witchcraftz]

Re: Fuel not filling to max

Filling the TDI I can get 54L if it's bone dry.

I'll text you and we'll figure a time for next week or weekend, I'm going to Whistler this weekend.

[All_Euro]

Re: Fuel not filling to max

My old 03 2.8 gli always take over 50L but I never saw this blue car go over 50L even when it had the 1.8T. When I did the engine swap I did find out the fuel pump and tank is different on this 04(didn't change it), maybe our late model GLi has a smaller tank? Does your gauge go to max when you fill up?

Late model GLI’s def have a 55L tank... and they’re completely plastic - thick plastic. I’ve put 53.xx L in my old tank more than once or twice. The tank I have now is supposed to be 62L but I regularly add 65L and it’s not reading as totally empty either. I’d try VCDS first and then think about valve or sending unit fixes.

[kujiwara]

Re: Fuel not filling to max

Have you pushed the vent button on the left side of your tank fill port? Thastll Hel you get a few more liters in by ventimg, but as for your guage....try Witchcrafts vag-com idea.

There's a button? Where is this magic button ahah

Filling the TDI I can get 54L if it's bone dry.

I'll text you and we'll figure a time for next week or weekend, I'm going to Whistler this weekend.

Sure! Whistler is so nice.

Late model GLI’s def have a 55L tank... and they’re completely plastic - thick plastic. I’ve put 53.xx L in my old tank more than once or twice. The tank I have now is supposed to be 62L but I regularly add 65L and it’s not reading as totally empty either. I’d try VCDS first and then think about valve or sending unit fixes.

yeah I'll do that, thanks for the tank info!

[funkin]

Re: Fuel not filling to max

Just a side note, I'm assuming you positioned the pump identical to the old one. If they aren't clocked right the float wouldn't have been or won't be in the proper position, giving you an inaccurate reading. Before spending too much time with vcds and running around trying to recalibrate it on a false reading, I'd fill the tank and try and rotate the pump, counter clockwise if I remember correctly, until you get to a full reading on your gauges. At that point I'd re-calibrate the gauge as doing so without having a full sweep on your level sensor float isn't going to help out a whole lot.