Fuel issues

Hi All

Not too sure if anyone has experienced this, but I have noticed according to the instrument panel, when the fuel gauge suggests that I have only 1/4 fuel left. The car tends to cut off, and will not start again. Assuming this is because the fuel isn't going to the engine.

This happened today and I went to the petrols stations to put 3 litres in a can and it started up the car. After this I drove down to the petrols station and filled up 25 litres.

So all in all I filled up 28 litres and all of a sudden I have a full tank and the car is running fine.

The petrol finishes but the fuel gauge suggests there's a 1/4 tank left….but I'm sure the petrol tank for cabby's hold up to 50 litres? If this the case somehow 22 litres of petrol isn't not travelling to the engine? Which doesn't make sense

Would welcomes anyone's experience or suggestions what I can do?

To avoid this problem I generally fill up after the field gauge suggests I have half a tank left….

Sounds as if your fuel gauge is wonky.

pre 84 Golfs/Cabriolets had a 10 gallon (37L) tank and a full sized spare.  Mid 84 production change took it to 50L (13 gallons) and a space saver spare.

Things to consider.
mid 84 CIS cars had a additional in-tank pump well up to 93.

The in-tank pump interconnect hose/vibration dampner is known to go soft and hole.  This allows fuels to go in the tank instead of to the main pump when low, filling it up tends to negate the efffect.

Floats on the sending units have been known to get holed and fill with fuel which makes them register wrong, as well as corrosion on the solder joints of the senders, and bad grounds.

Investigation is warranted, but only when the tank is 3/4 or 1/2 filled, as there will be massive fuel spillage if you have more than 3/4 in the tank when you pop the sender off.

Briano1234 said

Sounds as if your fuel gauge is wonky.

pre 84 Golfs/Cabriolets had a 10 gallon (37L) tank and a full sized spare.  Mid 84 production change took it to 50L (13 gallons) and a space saver spare.

Things to consider.
mid 84 CIS cars had a additional in-tank pump well up to 93.

The in-tank pump interconnect hose/vibration dampner is known to go soft and hole.  This allows fuels to go in the tank instead of to the main pump when low, filling it up tends to negate the efffect.

Floats on the sending units have been known to get holed and fill with fuel which makes them register wrong, as well as corrosion on the solder joints of the senders, and bad grounds.

Investigation is warranted, but only when the tank is 3/4 or 1/2 filled, as there will be massive fuel spillage if you have more than 3/4 in the tank when you pop the sender off.

Hey

Thanks for your reply. It's an 89 model so must be 50 litres. The fuel sending unit has been replaced twice yet the problem still persists.

So it could be this intank pump? I'm assuming this is in the fuel tank? Isit quite easy to access?

Is your car carb or fuel injection?

mark1gls said

Is your car carb or fuel injection?

It's a carb mate

Then there is no lift pump in the fuel tank.
Could be the fuel pick up in the tank gets blocked with dirt/rusty bits when driving as it's sucking up fuel, when the car stops and the pick up is no longer sucking up fuel the bits/blockage falls away from the pick up allowing the car to start again.
Or possibly the fuel pick is to high in the tank so it can't get to the petrol lower down in tank.  

mark1gls said

Then there is no lift pump in the fuel tank.
Could be the fuel pick up in the tank gets blocked with dirt/rusty bits when driving as it's sucking up fuel, when the car stops and the pick up is no longer sucking up fuel the bits/blockage falls away from the pick up allowing the car to start again.
Or possibly the fuel pick is to high in the tank so it can't get to the petrol lower down in tank.  

Thanks mark1gls - that also makes sense.

What is the best way to tackle this? Is the lift pump the part on the fuel sender unit? If so I did have the fuel sender unit changed…..

Have you actually filled the tank to the brim? Then when it starts to spluter refill it and you will know how much it holds, and how much it uses befor you have an issue.
It could also be faulty clocks.

volkswarren said

Have you actually filled the tank to the brim? Then when it starts to spluter refill it and you will know how much it holds, and how much it uses befor you have an issue.
It could also be faulty clocks.

Hey

Yea I normally fill up when the fuel gauge suggests half a tank is only left.

My engine cut off yesterday….the fuel gauge was at the first bar roughly. From that point onwards I had filled it up by 28 litres.  So mines a 50 litre tanks I don't get why the 22 litres isn't being picked up …..which could explain mark1gls points re fuel pick up could be high.

Another side point, if the petrol is half a tank (according to the fuel gauge) and if I happen to park the car at an angle. So the right side of the car is on the pavement and the left side is slanting down. The car won't start either…(hope that makes some sort of sense)

So which sender do you have?



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volkswarren said

So which sender do you have?



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It's the right one I believe

Ok i would ensure the pipe reaches the bottom of the tank


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I've seen instances were to get around the age old problem of debris in the tank from a rotted filler pipe the pickup on the level sender has been shortened and an aftermarket filter made to fit on the end.

You need to remove the sender and have a lookysee.

Also shine a torch into the tank and see if its full of water/rust/muck thats blocking the fuel lines.

I should also probably mention that the fuel filler neck was replaced four years ago as the old one was very rusty. It was a pain to fit this as it had to be cut and wielded.

I'll try and have a look in the fuel tank with a torch at some point this week. But my feeling is there is no debris in there (could be wrong!)

Just so I'm on the right page is the bit with the ball the fuel lifter pump and where the fuel pipe is attached is that the fuel pick up? Thanks

If the filler pipe was really rotten the tank will have taken some rust and muck in that should have been cleaned out.

The arm with the ball is the sender for the fuel gauge it floats on the petrol and goes up/down with the level of petrol.

The other one is the pickup for the petrol the goes to the pump on the side of the engine via the outlet on the top of the sender and the other pipe connector is for the return from the carb.

 

So got to the bottom to the fuel issue, it turns out it's not the fuel pump, or pick up. The fuel tank itself doesn't have baffle and it's a non genuine tank….

Does anyone know where I could source one?

I have this for sale

actually checked it and its aftermarket too and has no baffles.

Genuine tanks don't have baffles either as they are not needed, it's just early smaller Gti tanks which have baffles.

Not familiar with the Pierburg carb and set up but is not a swirl pot fitted or some sort of small tank which hold petrol on the carb?
My Webber on the my Mk1 Scirocco has a small tank which holds petrol in on the side of the carb?

edit…. Just had a look on line, is there a small tank just after the fuel pump and before the carb?

it’s near bracket 29C?

https://volkswagen.7zap.com/en/rdw/golf+cabriolet/goc/1989-44/1/129-37000/


looks some some thing like this? Not 100% sure what it does??


https://www.ebay.co.uk/itm/VW-GOLF-MK2-MK1-CABRIOLET-CADDY-SCIROCCO-FUEL-VAPOUR-SEPERATOR-026127177B-A72-/221481970011

 

mark1gls said

Genuine tanks don't have baffles either as they are not needed, it's just early smaller Gti tanks which have baffles.

Not familiar with the Pierburg carb and set up but is not a swirl pot fitted or some sort of small tank which hold petrol on the carb?
My Webber on the my Mk1 Scirocco has a small tank which holds petrol in on the side of the carb?

edit…. Just had a look on line, is there a small tank just after the fuel pump and before the carb?

it’s near bracket 29C?

https://volkswagen.7zap.com/en/rdw/golf+cabriolet/goc/1989-44/1/129-37000/


looks some some thing like this? Not 100% sure what it does??


https://www.ebay.co.uk/itm/VW-GOLF-MK2-MK1-CABRIOLET-CADDY-SCIROCCO-FUEL-VAPOUR-SEPERATOR-026127177B-A72-/221481970011

 

Hey

Yea that part is in the engine bay near the carb. (please note I have converted to a Webber carb now for the greater good!)

Apparently the carb models did have baffles?