1.4 Tdi Struggling to start..

I have a spare filter housing cover, I decided to totally block the bleed screw hole using the plastic screw with both o rings in place.
But before I blocked it up completely I poured some hot water into it with a little washing up liquid, I noticed very small air bubbles popping up around the inside of the screw housing, that's the reason I decided to just block it up with black mastic, I also blocked the three little holes that you can see on the underside of the cover with HYLOMAR Blue fuel resistant mastic so the fuel won't effect it.
I then put the cover with a new large O ring and tightened it up to 25nm.
Removed the clamps from the fuel lines and started the car eventually.
Still air bubbles flowing through the feed pipe into the pump. You can see hear that I have cut the edges of the screw holder to the same as the 27mm nut so I don't have to remove the screw first.
 

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It's probably been suggested before, but could the pump inlet clear pipe, be put into a coke bottle of diesel? Just to prove, hopefully, that the engine starts with no air leaks? If it start OK, next a temp, clear tube into the fuel tank?
Ignore my rambling if appropriate.
Mac
 
Studied up close, you can see what happens to a piece of metal situated in the road salt spray zone. The oxidation is gradually eating away at those spring clamps.

spring clamps.JPG


vehicleclips.co.uk

Audi Car Trim Clips, Fixings & Fasteners

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I'll check to see if they have clips that are suitable. :) 👍

Edit
Nope.

Name: Spring band clamp 14x12
Part Number N90768301

I can find non-VW parts but OEM parts are £2 per item and up. :(

Looking for these at all my usual sources online using
(Mikalor) sprung band clamp 14x12 listed but out of stock.:(
 
Last edited by a moderator:
PlasticMac said:
It's probably been suggested before, but could the pump inlet clear pipe, be put into a coke bottle of diesel? Just to prove, hopefully, that the engine starts with no air leaks? If it start OK, next a temp, clear tube into the fuel tank?
Ignore my rambling if appropriate.
Mac
Click to expand...
I've actually thought about doing that, I have some clear tubing that fits snuggly onto the metal inlet pipe on the tandem pump and it would reach going under the car then drop into the tank with the fuel gauge contraption removed, but then theres the problem of the returning fuel.
 
johnyfartbox said:
I have a spare filter housing cover, I decided to totally block the bleed screw hole using the plastic screw with both o rings in place.
But before I blocked it up completely I poured some hot water into it with a little washing up liquid, I noticed very small air bubbles popping up around the inside of the screw housing, that's the reason I decided to just block it up with black mastic, I also blocked the three little holes that you can see on the underside of the cover with HYLOMAR Blue fuel resistant mastic so the fuel won't effect it.
I then put the cover with a new large O ring and tightened it up to 25nm.
Removed the clamps from the fuel lines and started the car eventually.
Still air bubbles flowing through the feed pipe into the pump. You can see hear that I have cut the edges of the screw holder to the same as the 27mm nut so I don't have to remove the screw first.
Click to expand...
I don't blame you for doing that, that bleed screw is just a nuisance.. :oops:
 
Well I got a pipe connected to the inlet on the filter housing and into a fuel can, and no air!
IMG_20240331_170441_HDR.jpg
Next I managed to find enough pipe to run from the tank to the filter housing to bypass that pipe altogether. Again no air, so I connected up the feed to the tandem pump, bled the return line from the pump.

IMG_20240331_170332_HDR.jpg
The car looks like it's got a catheter fitted :p
IMG_20240331_183616_HDR.jpg
Anyway after a few attempts she caught and slowly fired up on all cylinders. I shut her off for 10 mins and tried again, yep another start no problem, this was looking promising. So I went up to the house, had some dinner, watched the second half of Man City vs Arsenal, and then went back and tried again. And she started hallelujah!! 😊
IMG_20240331_184759_HDR.jpg
So it seems to be the pipe from the tank to the filter housing. Whether all the messing with the sender has finished off the O ring in the connector, or whether the first time I clamped the pipes with mole grips has caused a bother I don't know.. At least I don't need a new tandem pump and now have a decent spare on as well.

Anybody know if the pipe is available from Audi? or is it a case of making one up somehow?

I might well have to drop the tank to change it over as well, but what the heck, I am so happy I have got to the bottom of this. I might be a bit daft, but I never give up, and persistance often pays off in the end 🧐
 
johnyfartbox said:
I really hope you have sussed it, but bear in mind, these things tend to give you false hope and, well you know where I'm going.
Click to expand...
Yes I know exactly what you mean, but after my debacle of concluding the pump was Kaput before, I decided I had to be absolutely meticulous in ruling things out properly. It helped that a mate turned up and gave me a hand as well, two minds is often better than one.

If you are having the same problem, then the same process would most likely show up your fault, all that is required is some 8mm and 10mm I/D clear pipe and a vacuum pump kit. Fuel goes from the tank to the filter to the tandem pump, so air has to be getting in somewhere on that route.
 
I also noticed that the car is up in the air at the back.
Normally with drain back it happens when the car is facing uphill and the fuel has to be pulled back up to the pump to start.
When facing downhill they tend to be easier to start.
Have you still got the clear tubing attached to the tandem pump input?
 
rotifer said:
Studied up close, you can see what happens to a piece of metal situated in the road salt spray zone. The oxidation is gradually eating away at those spring clamps.

View attachment 121600

vehicleclips.co.uk

Audi Car Trim Clips, Fixings & Fasteners

Secure your Audi's trim panels, bodywork, and vital components with precision-engineered fasteners. Our Audi Fasteners Collection offers top-quality plastic and metal fasteners, ensuring a seamless fit for a range of Audi models, including A3, A4, A6, and Q5. Manufactured to the exact...
vehicleclips.co.uk vehicleclips.co.uk

I'll check to see if they have clips that are suitable. :) 👍

Edit
Nope.

Name: Spring band clamp 14x12
Part Number N90768301

I can find non-VW parts but OEM parts are £2 per item and up. :(

Looking for these at all my usual sources online using
(Mikalor) sprung band clamp 14x12 listed but out of stock.
Click to expand...
It is a bit of a horror show isn't it :oops: Thanks for the close up picture 😯

I didn't realise there is supposed to be a cover over this area until I read it in one of the threads on here. Once I get it sorted will have to try to find something to protect it. I think Lanoguard is good for this sort of thing as well, stops rust and protects the rubber too.
 
I've been looking for fuel pipe connectors, these are the only ones I've found so far that seem to meet the spec required..


www.connect-consumables.co.uk

Connect Consumables 37214 Straight Fuel Line Quick Connectors 9.89 x 8mm 3pc Replaces OEM

Replacement Quick Connectors suitable for use on automotive fuel lines. Fits 8mm nylon hose, and 7.5mm rubber fuel hose. Made to SAE J2044-2009 standards
www.connect-consumables.co.uk www.connect-consumables.co.uk

The ones on the car are branded RAY and look a bit different, but I think these should work..

IMG_20240401_183655.jpg
 
Last edited:
I've been looking at anything I can find to get an idea of what the fuel hoses are like and where they go, and found this. Looking closely at the picture the fuel feed line from the sender seems to T off and also goes to some kind of junction or device.. So this may not be as straightforward as I hoped.. :oops:
www.ebay.co.uk

Audi A2 8Z 34 Litre Diesel Fuel Tank 8Z0201055D | eBay

Donor Car: 2003 Audi A2 1400cc. The New and Used Audi parts supplier. Audi Part Number: 8Z0 201 055 D. It may fit others.
www.ebay.co.uk

Okay scrap that, according to this diagram it's a bit simpler..

Audi Workshop Service and Repair Manuals > A2 > Power unit | Fuel supply system, diesel engines | Fuel supply, gas operation | Fuel supply system | 42 ltr. fuel tank with components - exploded view

A2 > Audi Workshop Service and Repair Manuals > Power unit | Fuel supply system, diesel engines | Fuel supply, gas operation | Fuel supply system | 42 ltr. fuel tank with components - exploded view
workshop-manuals.com

This might just be what I need, but could do with confirming part numbers. 🤔

Okay so this car is feb 2003 so it probably has the 34 liter tank, which is the more complicated ebay one..

Audi Workshop Service and Repair Manuals > A2 > Power unit | Fuel supply system, diesel engines | Fuel supply, gas operation | Fuel supply system | 34 ltr. fuel tank with components - exploded view

A2 > Audi Workshop Service and Repair Manuals > Power unit | Fuel supply system, diesel engines | Fuel supply, gas operation | Fuel supply system | 34 ltr. fuel tank with components - exploded view
workshop-manuals.com

According to this diagram, it is the simpler one again, this is very confusing..

Fuel line; fuel cooler; F 8Z-3-000 001>> Audi A2 (A2) 2002 year Audi EUROPA 201027

fuel line<br/>fuel cooler<br/>F 8Z-3-000 001>> Audi A2 (A2) 2002 year Audi EUROPA 201027 spare parts
audi.7zap.com audi.7zap.com
 
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I just realised today I have been confusing my two cars, this one is 2004 so it is definitely a 42 liter tank, which is the simpler setup, so that is a bonus.
Where I've got the car is so muddy now after that rain yesterday, and more to come tomorrow.. 🫣
IMG_20240402_114216_HDR.jpg
 
Our garden dissapeared underwater for a few days, in fact the whole village nearly floated away, anyway it's dried out a bit, so I decided to try a little fix on the grey one today.

I cut the feed connector off at the tank and replaced it with some plastic pipe. Then I drew fuel through to the feed pipe in the engine bay, and cleared the air out. So then I bled the return side.

After a few attempts she started up okay, so I left her for 10 minutes and tried again and off she went!

I was suspecting that tank connector as it has been on and off so many times lately, I wouldn't be surprised if the O ring had had enough.. If it still starts after a few hours, then I think I might have pinned down the problem. 🤔
IMG_20240407_111509_HDR.jpg
 
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