K-Jet Help Please!

it will also cut out randomly say at 50mph in 5th gear but its almost certain that it cuts out at high revs also though, I read that the dizzy and rotor arm may be a cause? im not sure about the pumps don't really know what sort of noise im listening for tbh, rather new and inexperienced,

It will be water in the fuel, getting in through a rotten filler neck. The clue is that after 20 minutes you can restart her. Water/fuel mixture will drain back to the tank.

Water causes the pressure to drop and then the injectors do not open, hence it stopping.

Get your hand up around the top of the filler neck and feel for corrosion.

Have the back seat out and undo the tank inspection/level sender cover. Get a magnet on a string in there and see what you pick up.

When my neck went I had about 2 litres of water in the tank.

Could also be electrical, but the starting ok again after 20 mins rules that out for me.

lhasadreams said

It will be water in the fuel, getting in through a rotten filler neck. The clue is that after 20 minutes you can restart her. Water/fuel mixture will drain back to the tank.

Water causes the pressure to drop and then the injectors do not open, hence it stopping.

Get your hand up around the top of the filler neck and feel for corrosion.

Have the back seat out and undo the tank inspection/level sender cover. Get a magnet on a string in there and see what you pick up.

When my neck went I had about 2 litres of water in the tank.

Could also be electrical, but the starting ok again after 20 mins rules that out for me.

After getting the back seat out I was able to hear the pump in the tank working, but only when it was running, shouldn't it work with the ignition on?
After taking the petrol cap off and moving the rubber seal I was able to see there is signs of rust around it. After I took the seat out and took the cap off I saw the fuel gauge sender but also 2 hoses aswell, do I have to take those off to get into the tank as im not sure at all? Have you got facebook or an email I can send you the pictures? Thanks for the help

Follow this simple guide to post pics up here:
http://vwgolfmk1.org.uk/index.php?page=postingPictures

Later cabbys had two pumps, the lift pump in the top of the tank and the main pump underneath the rear of the car. Both pumps only run when the engine is cranking or running. Some kjet relays cause the main pump to run for a short time when the ignition is turned on - it does not matter either way.

The reason VW did this was to consolidate to a single fuel tank design for both injection and carb models.

I think you have to remove those top two pipes to be able to twist the top plate to lift out the lift pump and fuel level sender. Be careful as there is a small filter that is only pushed on to the bottom of the lift pump.

It may be the lift pump that is failing, I have seen them run off the car but then fail under load when pumping fuel. Check the injection relay on the fuse box for signs of getting hot, failing pump(s) cause a much larger current draw, the relay gets very hot and in worst cases melts the solder and corrodes the relay plate contacts.

That doesn't look too good :-(

What is the actual filler pipe like behind that ?

Ye I thought the same im guessing ive got to undo those 3 screws to see that? they need some wd40 on them they wont move at all.

Its those 2 hoses that are connected, do they need to be disconnected to get it open?

Put it on axle stands and take the rear wheel off.
Get a torch and look up under the rear arch.
There will probably loads of caked on mud up there, remove the mud and then feel the filler neck for rust and holes

Yep, you will need to disconnect them to undo it. Pull the electrical connector off as well.

ah cheers mate, I wont be able to do that today unfortunately, but as soon as I have I will keep you updated, im hoping this is the problem rather than an electrical problem

The rust in the picture is on the body of the car not on filler neck, you need to look inside the hole for rust/holes. The rust means mud is trapped by the filler neck and will soon if not already creating rusty holes in the filler neck if not looked at soon, get your hands up there and pull and scrape the mud off and get a hose pipe under there but be careful if there is any holes in the filler neck not to spray anymore water into the fuel tank.
When you remove the two pipes in the other picture you will need 2 new fuel hose jubilee clips as you will have to destroy those clips in the picture to get them off. Just make sure the new clips are for fuel hose as they do differ from normal jubilee clips.
take the fuel cap off before removing the hoses and have a cloth ready as petrol will come out when the hoses are removed.

right guys a bit of an update. after looking into the tank I saw quite a lot of rust particles and a fair few big pieces within the tank, I looked at the filter but it was clean, is there any chance that these pieces are too big to go through the filter therefore blocking the petrol from being pumped? would this explain it cutting out at high revs? or does the pump not work any different at high revs? I don't think there is any water in the petrol should it be very noticeable? thanks

Could well be mate if there's large bits floating about

Apologies if you've mentioned before in the thread but what sort of condition is your filler neck in?

That confirms it, you are suffering from the number one Achilles heal of the Mk1 Golf - a rusty filler neck.

It also means that water will of entered the system along with the crud that you have observed.

The problem with water is that it will cause iron oxide or rust inside your metering head and anywhere else it comes in to contact with steel in the system.

You need to do the following:-

(1) Replace the filler neck with a brand new one.
(2) Drop the fuel tank and give it a really good clean out - some have have success with syphons and magnets on strings, but there is no replacement really for getting it upside down and swilled out.
(3) Replace the filter on the end of the lift pump.
(4) Disconnect the fuel return pipe at the metering head and run the pump(s) to clean the lines of any crud - catch the fuel in a container.
(5) Take the plunger out of the center of the metering head and inspect for rust - I would also undo each of the lines on the top of the metering head and look for crud or rust. You will need new copper washers to refit
(6) Pull the injectors from the head and run an injection test for both spray pattern and volume of delivery as per the Haynes manual.
(7) Run a pump volume delivery test as per Haynes.
(8) Run both control (warm and hot) and system pressure tests.

Basically you are trying to ensure that all crud/water/rust has been eliminated from the system and then check that fuel delivery rates and system/control pressures are good.

Rust in the injectors or metering head usually means they will have to be replaced - I fought with mine for a while but in the end had to get another one to get it running properly again.

Caddylove, you live pretty close to me, if you ever need to borrow/test anything for your GTi  pm me and I'll give you my address and phone number.
Safely say I have most items for, as rubjonny says, a 1985 on Golf.

lhasadreams said

That confirms it, you are suffering from the number one Achilles heal of the Mk1 Golf - a rusty filler neck.

It also means that water will of entered the system along with the crud that you have observed.

The problem with water is that it will cause iron oxide or rust inside your metering head and anywhere else it comes in to contact with steel in the system.

You need to do the following:-

(1) Replace the filler neck with a brand new one.
(2) Drop the fuel tank and give it a really good clean out - some have have success with syphons and magnets on strings, but there is no replacement really for getting it upside down and swilled out.
(3) Replace the filter on the end of the lift pump.
(4) Disconnect the fuel return pipe at the metering head and run the pump(s) to clean the lines of any crud - catch the fuel in a container.
(5) Take the plunger out of the center of the metering head and inspect for rust - I would also undo each of the lines on the top of the metering head and look for crud or rust. You will need new copper washers to refit
(6) Pull the injectors from the head and run an injection test for both spray pattern and volume of delivery as per the Haynes manual.
(7) Run a pump volume delivery test as per Haynes.
(8) Run both control (warm and hot) and system pressure tests.

Basically you are trying to ensure that all crud/water/rust has been eliminated from the system and then check that fuel delivery rates and system/control pressures are good.

Rust in the injectors or metering head usually means they will have to be replaced - I fought with mine for a while but in the end had to get another one to get it running properly again.

Oh dear that seems a hell of a lot of work I don't think im capable of it really, well im out of my depth on all the volume tests etc, Im not sure what to say really, but thank you ever so much for helping me identify the problem, thanks mate

PeteB said

Caddylove, you live pretty close to me, if you ever need to borrow/test anything for your GTi  pm me and I'll give you my address and phone number.
Safely say I have most items for, as rubjonny says, a 1985 on Golf.

That's ever so kind of you mate, im in Parson Drove nr Wisbech if you know where that is?

So as a minimum you need to do the following:

(1) Replace the filler neck.
(2) Get as much crud out of the tank as possible using a magnet and syphon. You will have water in there so try and get it out.

(3) Replace the lift pump filter and the fuel filter in the engine bay - why the filter is disconnected you could manually run the pump to empty the tank. My filter had a lot of water in it.

(4) Fill her up and see how she goes.

Good luck getting her sorted.

If it was me I would fit a new fuel filler neck (cabriolet necks are differnet to tin tops so are more expensive) new rubber hose joining the fuel tank to the filler neck as if it the oringinal one it will need replacing, 2 new jubliee clips (the old ones will be rusty by now) for the filler neck hose and then fit a new lift pump (around £25) from inside the fuel tank and drop a magnet in the fuel tank and leave it in there to catch all the bits of rust, dont drop the magnet near the pick up/fuel gauge sender as it might affect the fuel gauge, new fuel filter in the engine bay then see how it goes.