Changing Petrol In-tank Fuel Pump
- Thread starter Philip
- Start date
Can't find a 'how to' but it's fairly easy. Disconnect the battery, remove the back seat base, remove the access panel, make note of the wiring connections and fuel pipes before disconnecting them, I think the pump module lock ring just needs half a turn to undo it.
Cheers Spike
Cheers Spike
SoftwareAndSwarfega
Member
I know this is an old thread, but having done this job yesterday, on my FSI, I thought I’d give a few pointers to anyone else that tries it.
- Disconnect your battery!
- Having folded back the carpet under the o/s rear seat, the circular plastic cover that you will see needs a quarter turn counter clockwise to remove it.
- You will then see the top of the fuel sender unit, with an electrical connector and fuel pipes attached.
- To remove the electrical connector, as with all these VAG connectors, you should initially press down firmly on the connector whilst gently pushing/squeezing the top of the locking tab on the side inwards with one finger (no more than a couple of millimetres - don’t snap it!) so that it disengages. Then, whilst still squeezing the tab, pull upwards and the connector will come off with a gentle popping sound.
- Fuel lines, one blue and one black, each have a locking tab at the base of their elbow. You need to depress the tab quite a lot and then pull gently upwards to remove. I tucked each one under the rim of hole so that they are out of the way for the next step.
- There is a large, castellated locking ring holding the sender onto the tank. It needs to be unscrewed, counter clockwise, a good number of turns, in order to remove it. You initially think, it looks like it should unscrew by hand, but I found mine was impossible to turn with my bare hands, and access for your fingers is very limited anyway. I initially fashioned a tool that spanned the width of the ring and engaged with the castellations, but again found it impossible to move. The castellations are not very high, so it is hard to get any purchase. In the end, I had to drift it off with a piece of hardwood and a mallet, initially hitting the castellation positioned at about 4 o clock when kneeling in the boot facing the back of the drivers seat. It needed a good few hefty whacks before it started to move. Nb. You need to be careful when drifting that you do not slip and hit one of the fuel pipe connections.
- Once the castellated ring is removed, you should be able to wiggle the sender out carefully. Note it has a rubber seal (mine was falling to pieces from exposure to fuel) and there were fragments in the tank) and has corregated flexible pipes that might catch on the edges of the hole as you remove the unit as a whole. My pipes were all very brittle and every one was broken
, and the vibrations from the drifting won’t have helped.
I haven’t refitted yet, but come the time it will be a reverse of the above.
Hope this helps someone.
John
- Disconnect your battery!
- Having folded back the carpet under the o/s rear seat, the circular plastic cover that you will see needs a quarter turn counter clockwise to remove it.
- You will then see the top of the fuel sender unit, with an electrical connector and fuel pipes attached.
- To remove the electrical connector, as with all these VAG connectors, you should initially press down firmly on the connector whilst gently pushing/squeezing the top of the locking tab on the side inwards with one finger (no more than a couple of millimetres - don’t snap it!) so that it disengages. Then, whilst still squeezing the tab, pull upwards and the connector will come off with a gentle popping sound.
- Fuel lines, one blue and one black, each have a locking tab at the base of their elbow. You need to depress the tab quite a lot and then pull gently upwards to remove. I tucked each one under the rim of hole so that they are out of the way for the next step.
- There is a large, castellated locking ring holding the sender onto the tank. It needs to be unscrewed, counter clockwise, a good number of turns, in order to remove it. You initially think, it looks like it should unscrew by hand, but I found mine was impossible to turn with my bare hands, and access for your fingers is very limited anyway. I initially fashioned a tool that spanned the width of the ring and engaged with the castellations, but again found it impossible to move. The castellations are not very high, so it is hard to get any purchase. In the end, I had to drift it off with a piece of hardwood and a mallet, initially hitting the castellation positioned at about 4 o clock when kneeling in the boot facing the back of the drivers seat. It needed a good few hefty whacks before it started to move. Nb. You need to be careful when drifting that you do not slip and hit one of the fuel pipe connections.
- Once the castellated ring is removed, you should be able to wiggle the sender out carefully. Note it has a rubber seal (mine was falling to pieces from exposure to fuel) and there were fragments in the tank) and has corregated flexible pipes that might catch on the edges of the hole as you remove the unit as a whole. My pipes were all very brittle and every one was broken
, and the vibrations from the drifting won’t have helped.I haven’t refitted yet, but come the time it will be a reverse of the above.
Hope this helps someone.
John
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PlasticMac
Member
What symptoms pointed to the electric pump being a suspect? Just interested in anything FSI specific.I know this is an old thread, but having done this job yesterday, on my FSI, I thought I’d give a few pointers to anyone else that tries it.
- Disconnect your battery!
- Having folded back the carpet under the o/s rear seat, the circular plastic cover that you will see needs a quarter turn counter clockwise to remove it.
- You will then see the top of the fuel sender unit, with an electrical connector and fuel pipes attached.
- To remove the electrical connector, as with all these VAG connectors, you should initially press down firmly on the connector whilst gently levering the tab on the side outwards with one finger (no more than a couple of millimetres - don’t snap it!). Then, without removing your finger from the tab, pull upwards and the connector will come off with a gentle popping sound.
- Fuel lines, one blue and one black, each have a locking tab at the base of their elbow. You need to depress the tab quite a lot and then pull gently upwards to remove. I tucked each one under the rim of hole so that they are out of the way for the next step.
- There is a large, castellated locking ring holding the sender onto the tank. It needs to be unscrewed, counter clockwise, a good number of turns, in order to remove it. You initially think, it looks like it should unscrew by hand, but I found mine was impossible to turn with my bare hands, and access for your fingers is very limited anyway. I initially fashioned a tool that spanned the width of the ring and engaged with the castellations, but again found it impossible to move. The castellations are not very high, so it is hard to get any purchase. In the end, I had to drift it off with a piece of hardwood and a mallet, initially hitting the castellation positioned at about 4 o clock when kneeling in the boot facing the back of the drivers seat. It needed a good few hefty whacks before it started to move. Nb. You need to be careful when drifting that you do not slip and hit one of the fuel pipe connections.
- Once the castellated ring is removed, you should be able to wiggle the sender out carefully. Note it has a rubber seal (mine was falling to pieces from exposure to fuel) and there were fragments in the tank) and has corregated flexible pipes that might catch on the edges of the hole as you remove the unit as a whole. My pipes were all very brittle and every one was broken
I haven’t refitted yet, but come the time it will be a reverse of the above.
Hope this helps someone.
John
Mac.
SoftwareAndSwarfega
Member
Hi. It was actually your post about the fuel rail pressure (
Thread 'FSI Low Fuel Rail Pressure? Possibly not HPFP ...'
https://www.a2oc.net/community/index.php?threads/fsi-low-fuel-rail-pressure-possibly-not-hpfp.52454/) as I’ve been having hot start issues for a while and I’ve tried everything else that has mentioned as a possible cause, namely cam position sensor, temperature sensor and crankshaft speed sensor in that order.
Looking at the state of the pipes (the broken ones I mentioned) I am hoping that the replacement pump and pipes will be the fix, as I figure that one or more of them were cracked/broken before I removed it and whilst they were able to deliver the necessary amount most of the time during normal driving, they couldn’t handle the pressure of the hot start.
I also have the issue of bogging down at high revs.
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PlasticMac
Member
Hi. It was actually your post about the fuel rail pressure (
Thread 'FSI Low Fuel Rail Pressure? Possibly not HPFP ...'
https://www.a2oc.net/community/index.php?threads/fsi-low-fuel-rail-pressure-possibly-not-hpfp.52454/) as I’ve been having hot start issues for a while and I’ve tried everything else that has mentioned as a possible cause, namely cam position sensor, temperature sensor and crankshaft speed sensor in that order.
Looking at the state of the pipes (the broken ones I mentioned) I am hoping that the replacement pump and pipes will be the fix, as I figure that one or more of them were cracked/broken before I removed it and whilst they were able to deliver the necessary amount most of the time during normal driving, they couldn’t handle the pressure of the hot start.
I also have the issue of bogging down at high revs.
Mac.
Hi, where did you get replacement pump? My FSI is cutting out and spluttering with a humming noise coming from the tank, is the pump a metal canister type?
Mac.
PlasticMac
Member
Fuel Pump For Seat / Alhambra / Arosa / Leon / Toledo / P3031.1
Fuel Pump For seat P3031.1 Make Model Year Seat Alhambra 1.8i Turbo 20V 98 Seat Alhambra 2.0i 98 Seat Alhambra 2.0i 98-00 Seat Alhambra 2.8i V6 2000
SoftwareAndSwarfega
Member
You may find, as I did, that the pipes etc for the surrounding casing have perished and cracked. In the end, I purchased this pump https://justgermanparts.co.uk/produ...petrol-1-6-1-8-2-0-petrol-vw-audi-seat-skoda/ and fitted it to my FSI and it is working perfectly - but I did need to reuse the old sender float, as the fuel tank gauge reading was reversed otherwise (I think this has been mentioned elsewhere).
Thanks for the info, I'll look into it, cheers.
Hi, I hope to get mine changed this weekend as I bought the pump you recommended but I just want to know what was happening with your car to deem replacing this pump as the cure?
SoftwareAndSwarfega
Member
Hi
My car exhibited a number of symptoms, including a feeling that it was bogging down at certain points in the revs range, typically when in higher gears. It’s hard to describe, but it just felt like the engine was not getting enough of something that it needed and was hesitating rather than misfiring. However, the primary issue that I was pulling my hair out over was the fact that, when up to temperature, and seemingly out of nowhere, the engine would lose power and stop - forcing me or my wife to pullover in a hurry. It could then not be restarted until the engine had cooled to about 70 degrees - I literally had to wait an hour for it to cool and then it would restart.
All of these issues have been resolved by the new pump. I still have other “minor” issues such as the oxygen sensor causing the EML light - but that is nothing to do with the pump! At least nowadays I can jump in and the car will start every time, regardless of temperature.
Best of luck and let us all know how it goes.
John
Similarly, the engine started to randomly cut out at motorway speeds - after a few occasions of this, it wouldn’t restart. The pump that failed was a precautionary replacement fitted when I went through the car, so I didn’t suspect it (could still hear it priming); VCDS found nothing and the consensus was crank sensor - which £300 later, it wasn’t…
SoftwareAndSwarfega
Member
You’ll have seen that I also replaced my crank sensor - which is a pig of a job - to no avail. I would warrant that one or more of the corrugated flexible pipes on your pump assembly have deteriorated over time to the point of having cracks, and the pump is basically trying to push petrol through a sieve…
PlasticMac
Member
Log, on a varied drive, a few likely suspects, fuel rail pressure, coolant temperature, flap position, etc. Might well point you to the culprit.
Mac.
Hi, did you swop the floats over? how did you remove old float from your old pump, i changed the wires round thinking that's what you meant but looks like i maybe wrong.
Hi all,
Just to update you all on my problem with fuel system. Changed the in tank delivery pump but didn't make much difference, so for last couple of weeks or so i have been running with the new in tank pump, different E5 petrol and additive added into tank as my fuel filter was black with dirt but now I think my issue is with my HPFP, only last week, I drained remaining fuel from old tank pump and along with the dirt I think it looks like there is metal filings in the petrol and it leads me to think that my pump is on its way out, anyone think the same please or not??
Just to update you all on my problem with fuel system. Changed the in tank delivery pump but didn't make much difference, so for last couple of weeks or so i have been running with the new in tank pump, different E5 petrol and additive added into tank as my fuel filter was black with dirt but now I think my issue is with my HPFP, only last week, I drained remaining fuel from old tank pump and along with the dirt I think it looks like there is metal filings in the petrol and it leads me to think that my pump is on its way out, anyone think the same please or not??
Attachments
PlasticMac
Member
I have no idea where that contamination comes from, but it needs to be cleaned out, then a new fuel filter should be fitted.
Anything like metal filings in the tank will not have come from the the HPFP. I'm not sure of the construction of the in tank electric pump, but I'd be surprised if it came from there.
I think the fuel tank needs to be removed and cleaned. A job for a specialist, in my opinion, as it is high risk.
The only way to check out the HPFP is via measuring blocks in Group 140.
Mac.
Edit: Although HPFP pressure could be checked with a pressure gauge, the required pressure is controlled by the ECU, so with a pressure gauge, you can see the actual pressure, but have no idea if it's correct. Group 140 shows both the ECU specified value and the actual value.
Anything like metal filings in the tank will not have come from the the HPFP. I'm not sure of the construction of the in tank electric pump, but I'd be surprised if it came from there.
I think the fuel tank needs to be removed and cleaned. A job for a specialist, in my opinion, as it is high risk.
The only way to check out the HPFP is via measuring blocks in Group 140.
Mac.
Edit: Although HPFP pressure could be checked with a pressure gauge, the required pressure is controlled by the ECU, so with a pressure gauge, you can see the actual pressure, but have no idea if it's correct. Group 140 shows both the ECU specified value and the actual value.
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Thanks PlasticMac,
I carried out a diagnostic on VCDS on fuel pump last night, see attached report and I would appreciate if you would check it and let me know your thoughts on it.