Never a full tank
#1
08-26-2018, 10:32 AM
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Never a full tank
Bought a 2003 S Type R a few months back. Has 119K on the odometer. Finally got around to needing to fill up the car and noticed I can only get 3/4 tank full. Have used several different stations but all with same result. Any suggestions? I'm thinking evap can issues or valve?
Thanks in advance.
Thanks in advance.
#2
08-26-2018, 12:01 PM
Veteran Member
Is the tank only accepting a partial fill? Or does it take the full amount but you've got an indication problem?
The tank is saddle-shaped, with a level sender for each side. The Rear Electronic Control Module (RECM) reads both sides and outputs a single combined value. Wiring diagrams here, courtesy of Gus. Select your year and look at section 07.1:
JagRepair.com - Jaguar Repair Information Resource
From the RECM, you can use an ohmmeter to read each side individually.
Does the gauge seem accurate below 3/4? If so, run it down fairly low and see how much fuel it will take to refill. If you know the tank capacity and have a reasonable estimate of the quantity before refilling, the amount added should help determine what is happening.
Also, after the tank stops filling, have you tried pulling the nozzle back a little bit? At many stations, the automatic shutoff is very touchy and kicks off too soon. With my old pickup, I almost always have to back out the nozzle a little bit to fill the tank completely. It's acted like that for years. If the nozzle has a vapor recovery bellows, you may have to compress it slightly to trick the pump into thinking the nozzle is fully seated or the pump won't run.
Last edited by kr98664; 08-26-2018 at 01:02 PM.
#3
08-26-2018, 01:33 PM
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#4
08-26-2018, 01:57 PM
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It does not appear to be an indication problem, but rather the pump shuts off and will not accept additional fuel. The most I can get into the car is 12.2 gallons. I've tried the pulling back the bellows, but will give it one last try before exploring other options. Thanks for the insight so far.
#5
08-27-2018, 12:51 PM
Veteran Member
Next time you fill the tank, set your odometer to show range to empty. The range is based on the fuel level and recent fuel consumption patterns. If the sender arm travel.was blocked in such a way that it couldn't mechanically travel to full, the float would be submerged if the tank was physically full. The gauge (and range to empty) would not change until you had consumed a quarter of the tank and then the float could track the actual fuel level.
However, this isn't a perfect test because of the two senders in a saddle-shaped tank. The total quantity is based on the sum of the two senders. Assuming (Danger! Danger!) only one is at fault, I'm not sure what that would do to the rate of change for the gauge and the range to empty calculation. I THINK the rate of change would be half of normal, but that's just a guess.
And then, of course, you could have an inaccurate reading caused by an electrical problem with a sender, not a mechanical issue. I'm also not sure how that would affect the gauge with two senders in the circuit. Kinda makes my head spin. Even with no.clear advice, I'm just trying to make sure you don't automatically rule out an indication problem.
Back to an actual physical condition, with the tank only 3/4 full. How about this idea?: Fill a portable.gas can with about 5 gallons of fuel. Fill the car's tank as normal at the gas station, and then head straight home to the waiting gas can. See if you can SLOWLY fill the last quarter of the tank while it still reads 3/4. That would provide a big clue how best to proceed.
Last edited by kr98664; 08-27-2018 at 03:55 PM.
#6
08-27-2018, 02:32 PM
You may be in uncharted territory here. I don't remember hearing any reports of other S-Types not taking fuel. I don't know of any slam dunk method to diagnose exactly what is happening. Until you have positive proof, don't just rule out an indication problem. As far as I know, there's nothing in the car that closes off the tank filler. That would lead me to think you've got an indication problem or something in the vent system is erroneously shutting off the pump early.
Next time you fill the tank, set your odometer to show range to empty. The range is based on the fuel level and recent fuel consumption patterns. If the sender arm travel.was blocked in such a way that it couldn't mechanically travel to full, the float would be submerged if the tank was physically full. The gauge (and range to empty) would not change until you had consumed a quarter of the tank and then the float could track the actual fuel level.
However, this isn't a perfect test because of the two senders in a saddle-shaped tank. The total quantity is based on the sum of the two senders. Assuming (Danger! Danger!) only one is at fault, I'm not sure what that would do to the rate of change for the gauge and the range to empty calculation. I THINK the rate of change would be half of normal, but that's just a guess.
And then, of course, you could have an inaccurate reading caused by an electrical problem with a sender, not a mechanical issue. I'm also not sure how that would affect the gauge with two senders in the circuit. Kinda makes my head spin. Even with no.clear advice, I'm just trying to make sure you don't automatically rule out an indication problem.
Back to an actual physical condition, with the tank only 3/4 full. How about this idea?: Full a portable.gas can with about 5 gallons of fuel. Fill the car's tank as normal at the gas station, and then head straight home to the waiting gas can. See if you can SLOWLY fill the last quarter of the tank while it still reads 3/4. That would provide a big clue how best to proceed.
Next time you fill the tank, set your odometer to show range to empty. The range is based on the fuel level and recent fuel consumption patterns. If the sender arm travel.was blocked in such a way that it couldn't mechanically travel to full, the float would be submerged if the tank was physically full. The gauge (and range to empty) would not change until you had consumed a quarter of the tank and then the float could track the actual fuel level.
However, this isn't a perfect test because of the two senders in a saddle-shaped tank. The total quantity is based on the sum of the two senders. Assuming (Danger! Danger!) only one is at fault, I'm not sure what that would do to the rate of change for the gauge and the range to empty calculation. I THINK the rate of change would be half of normal, but that's just a guess.
And then, of course, you could have an inaccurate reading caused by an electrical problem with a sender, not a mechanical issue. I'm also not sure how that would affect the gauge with two senders in the circuit. Kinda makes my head spin. Even with no.clear advice, I'm just trying to make sure you don't automatically rule out an indication problem.
Back to an actual physical condition, with the tank only 3/4 full. How about this idea?: Full a portable.gas can with about 5 gallons of fuel. Fill the car's tank as normal at the gas station, and then head straight home to the waiting gas can. See if you can SLOWLY fill the last quarter of the tank while it still reads 3/4. That would provide a big clue how best to proceed.
#7
08-27-2018, 03:51 PM
Senior Member
thread sounds very similar, From an XK but might relate to an Stype https://www.jaguarforums.com/forum/x...w-fill-205589/
And another thread. https://www.jaguarforums.com/forum/x...letely-192114/ this was with a quick search. Take some time and keep searching there might be more https://www.jaguarforums.com/forum/x...letely-192114/
And another thread. https://www.jaguarforums.com/forum/x...letely-192114/ this was with a quick search. Take some time and keep searching there might be more https://www.jaguarforums.com/forum/x...letely-192114/
Last edited by MyBlackCat; 08-27-2018 at 03:56 PM.
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#8
08-27-2018, 06:40 PM
Veteran Member
No, worse. I am a mechanic.
Do you know the difference between an engineer and God?
Got to thinking more about the gas can idea. I think that's the best tactic to start troubleshooting. Maybe ten minutes of time and you'd quickly know if the indication system is accurate. If good, then you could concentrate on the fill/vent system.
#9
08-28-2018, 07:09 AM
Me Too Movement
I am on my 2nd S-Type. A 2006 first and now a 2005. The first one never had a problem with gas filling, but this one, and I have had it more than a year now, has a problem filling the tank every time. I sm attempting to fill the tank after I have driven the car for over a week, so I know the gauge that is telling me the tank is low is correct. I can only put about 3 - 4 gallons in before the pump's automatic shut-off stops the flow. I pause for a bit and start again slowly, having it shut off many more times along the way. I actually stop when I can hear it is near the top and the pump's readout is at about what I think should be a full tank. I am using the same gas stations I did for my last car.
#10
08-28-2018, 07:42 AM
Veteran Member
#12
08-28-2018, 04:25 PM
No, worse. I am a mechanic.
Do you know the difference between an engineer and God?
Got to thinking more about the gas can idea. I think that's the best tactic to start troubleshooting. Maybe ten minutes of time and you'd quickly know if the indication system is accurate. If good, then you could concentrate on the fill/vent system.
Do you know the difference between an engineer and God?
Got to thinking more about the gas can idea. I think that's the best tactic to start troubleshooting. Maybe ten minutes of time and you'd quickly know if the indication system is accurate. If good, then you could concentrate on the fill/vent system.
#13
08-28-2018, 04:34 PM
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#14
08-28-2018, 09:33 PM
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OK. Update on the fuel filling issue. I ran the car down to less than 15 total miles left. I filled up the car at another gas station that allowed me to rotate the pump handle to different angles. Got 12.8 gallons in. Usually it is around 12 gallons, but I'm sure the .8 came from running the car down to almost bone dry. I also filled up a 5 gallon racing fuel jug to see if I could squeeze any more fuel in the tank. I got back to the house (4 min from gas station) and was only able to squeeze in another .75 gallon or so by letting the fuel basically drip into the tank. After several minutes of this procedure I gave up. It has to be a fuel vapor issue of some sort. I'll update when I begin to dig into that area. Other than that this car is a blast to drive. Mine came with an aftermarket exhaust so it sounds plain nasty at full throttle. Unsuspecting Mustangs and other small hot rods have no idea why they can't keep up with the 4 door British Saloon!
#15
08-28-2018, 10:22 PM
Veteran Member
Look at it this way. The slow drip into the tank changes only one part of the equation: The fill rate. With the gas station pump, you can only slow the fill rate so much. The pump has a minimum flow no matter how gently you squeeze the handle. And then above a certain fill rate, the displaced air creates a back pressure above the threshold to shut off the pump. With the gas can, you can slow the fill rate below a snail’s pace and have virtually no back pressure. If your tank was only 3/4 full, couldn’t you theoretically top it off one drop at a time?
That’s what makes me think the tank is really full but only showing 3/4 on the gauge. Is anybody else seeing this? Am I out in left field with this line of reasoning? There’s no valve on the car to shut off filling, is there? If there is, my theory is all wet and I’ll take my well-deserved lumps.
#16
08-28-2018, 10:57 PM
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Thanks for humoring me and trying that. However, wouldn’t the results point to an indication problem?
Look at it this way. The slow drip into the tank changes only one part of the equation: The fill rate. With the gas station pump, you can only slow the fill rate so much. The pump has a minimum flow no matter how gently you squeeze the handle. And then above a certain fill rate, the displaced air creates a back pressure above the threshold to shut off the pump. With the gas can, you can slow the fill rate below a snail’s pace and have virtually no back pressure. If your tank was only 3/4 full, couldn’t you theoretically top it off one drop at a time?
That’s what makes me think the tank is really full but only showing 3/4 on the gauge. Is anybody else seeing this? Am I out in left field with this line of reasoning? There’s no valve on the car to shut off filling, is there? If there is, my theory is all wet and I’ll take my well-deserved lumps.
#17
08-29-2018, 05:58 AM
Veteran Member
There must be a TSB for what I experienced. Jaguar knew what it was at the time. I know there's an old thread about it. Search is your friend.
The fix is probably not cheap at this point though. As I remember there are several versions of gas tanks and pumps inside of them. I beleive they're plastic blow molded things so as to fit in tight places. Jaguar & plastic
#18
08-29-2018, 06:46 AM
Veteran Member
#19
08-29-2018, 06:54 AM
Veteran Member
Be afraid. Be very afraid. When you start to agree with my logic, well...
I’m still not 100% convinced of my theory, but things are leaning that way. I wish there was some simple way to verify the actual quantity present. All I can think at the moment is to remove the covers where the pumps are and check that way. Sounds like too much work, though. Maybe I’ll have a better idea after finishing my pancakes.
I’m still not 100% convinced of my theory, but things are leaning that way. I wish there was some simple way to verify the actual quantity present. All I can think at the moment is to remove the covers where the pumps are and check that way. Sounds like too much work, though. Maybe I’ll have a better idea after finishing my pancakes.
#20
08-30-2018, 03:48 AM
Senior Member
You can display the raw data from the two fuel tank senders on the dashboard display in test mode.
1. Press and hold down the 'Trip' button on the end of the stalk.
2. Turn the ignition on (position two)
3. Release the 'Trip' button when the dashboard display switches to 'ENGINEERING TEST MODE’
4. Use the the trip computer ‘MLS/KMS button (up) or the the trip computer ‘A/B’ button (down) to change the readout.
5. Fuel RAW 1 and Fuel RAW 2 should be about the same on flat ground.
6. Rock the car and they should vary as the fuel moves about in the tank.
If one of the RAW readings does not move when you rock the car then it is a jammed sender unit.
Depending on fuel level the readings should be between 27 and 240.
A reading under 10 is a short circuit.
A reading of 255 indicates an open circuit.
My guess would be that one of the tank senders is jammed or is open circuit.
To exit the test mode just turn the ignition off or press the trip button for more than 3 seconds.
I hope this helps.
1. Press and hold down the 'Trip' button on the end of the stalk.
2. Turn the ignition on (position two)
3. Release the 'Trip' button when the dashboard display switches to 'ENGINEERING TEST MODE’
4. Use the the trip computer ‘MLS/KMS button (up) or the the trip computer ‘A/B’ button (down) to change the readout.
5. Fuel RAW 1 and Fuel RAW 2 should be about the same on flat ground.
6. Rock the car and they should vary as the fuel moves about in the tank.
If one of the RAW readings does not move when you rock the car then it is a jammed sender unit.
Depending on fuel level the readings should be between 27 and 240.
A reading under 10 is a short circuit.
A reading of 255 indicates an open circuit.
My guess would be that one of the tank senders is jammed or is open circuit.
To exit the test mode just turn the ignition off or press the trip button for more than 3 seconds.
I hope this helps.
Last edited by M-e-l-l-o-w; 08-30-2018 at 06:07 AM.