My car won't start :(
 

Hi.

Very frustrated at the moment. My car won't start. Ran fine this morning. Went to mum's to help her out. Got back home, parked the car across the road because next door is having new driveway and fence put in.

Went to start car an hour and a half later and it won't start.

Can't vag com until I sort a laptop that has battery power, perhaps tomorrow afternoon.

Symptoms: Nearly started first couple of times, now just cranks with no sign of life. Strong crank. Can't smell fuel.

Yesterday the ASR and CAT light came on and the car ran roughly. So I shut it off straight away. ASR light went off, CAT light stayed on. Went a couple hundred metres. Turned car off, restarted and CAT light went out. Related to my problem?

Please suggest where to start looking / what to start looking at.

Thanks.

Sounds like possibly a fuel pump.

Thanks for your reply. Yes, that is what I have been reading in the internet. Do you know if Vag Com will indicate this in some way?


What would be the best way to check for this cause on the '98 D2 S8?

Thanks again.

And possibly just the old pump seating/sealing issue.

In which case, how much fuel is in the tank? If it's less than half full, might be worth adding a gallon or two to see if it runs.

I could be wrong but I think you should be able to hear the fuel pump run (briefly) when you turn the ignition on. Might need to stick your head in the boot to hear it, while someone turns the ignition on for you.

+++ Thanks for that tip! The blood has gone to my head and I am not thinking properly. I will have a listen in the boot. Is that the usual failure mode for the pump - does not run?

The petrol tank is full minus 60km.

Is there somewhere under the hood that I can unbolt to check for fuel? Can I spray something somewhere to simulate fuel delivery?

Thanks again for everyone's help.

Is that easy to check or inspect visually?

If you enjoy lying in the boot, contorted and getting high on petrol fumes, it's a wonderful job. Otherwise it's a bloody awful job to do. :D

It's easy to determine if that's the problem though ... just put a few more gallons of fuel in. And if that does turn out to be the problem, the workaround is to keep half a tank or more of fuel in the car at all times. I drove mine like that for a few years. It can be fixed but I think there's probably a knack to it. After a few failed attempts (by myself and 2 different mechanics) I just gave up and replaced the entire tank.

So extremely unlikely it's the seating problem. ;)
(Unless that 60km involved the most aggressive driving imaginable! :tuttut: )

I can see this being me in my not too distant future...

I never let the fuel get below half a tank on any of the Audis that I have owned. I have only driven 60km since filling the beast so that means I have only used 7.8 litres out of a full tank. I have read that you can put a bit more fuel in the tank to fill up a 'cup' that the pump sits in so I might try that.

I have also read that I can squirt starting fluid somewhere and possibly get the car to start, so that would be a bonus right now.

Another thing that I have just read is that I can reverse the electrical connection at the terminals on the fuel pump to make it run backwards for a second or two, and that *may* unjam the pump, should the failure be due to a certain commutator problem.


Ouch!

:ROFL: +++

Thanks for discounting the seating problem for me.

I promise that I was only driving aggressively just the once up a lovely twisty hill for no more than 30 seconds! Otherwise, sedate city driving in traffic I am afraid.

Ah, yes, I missed that bit.

I don't know, I'm sure I could use up half a tank in 60km if I tried :ROFL:

This mirrors my experience exactly. Fuel gauge was on the 3rd segment (out of 12, I think) when she ran out of fuel, so probably around 50-60 miles of range showing. Fuel pump replaced and subsequent return trips to the garage for new seal kit and re-seat. Still runs out of fuel at the 3rd segment but I'm used to that by now. Not prepared to spend any more money on that particular problem.

New fuel pump is slightly more buzzy than before and you should be able to hear it prime when turning the key to ignition on.

Hope you get your problem sorted.

Just to add some background info:

Mine was a combination of two isssues, namely fuel pump failure and then the subsequent problem of 'running out of fuel' when the gauge shows a quarter full. Once the fuel pump was replaced, and having effectively run out of petrol, the car showed signs of attempting to start on a couple of occasions and then pretty much nothing else. Strong cranking from the battery/starter motor. Low-loaded back to the garage to check (I was convinced there was fuel in there) and then discovered thanks to this forum about the fuel tank issue where part of the system to maintain equal levels on both sides of the fuel tank isn't working properly in my case. MJ seems to think it's one of the fuel return pipes possibly being blocked.

When my fuel pump borked, there were no prior warning signs apart from the car not moving lol, just a couple of spurts forward before the car stalled in the middle of a nicely-painted diagonal striped box junction.

Good luck with your investigations. It's probably worth updating your profile/signature to reflect where you are geographically, as someone on the forum may be able to assist with a quick VAGCOM or OBDEleven unit.

Done! Thanks for the tip :)

Marty! You visiting Newcastle, NSW anytime soon? If so, bring your Vag Com cable and working laptop please!

Also worth considering crankshaft position sensor, which recently went on mine. We thought it was fuel pump and got it recovered, changed the fuel pump, seemed to fix it and then it went wrong again and did the same thing, but that pulled a code which gave it away so do scan the car before you try anything else!

Thank you! I do intend to scan as soon as I am able. I posted a question in the Vag Com section and would appreciate any input on that if anyone has an idea. Thank you lovely people!

can I do this?

***UPDATE*** Starting Fluid allows the car to start momentarily.
 

Updating this thread to report some progress in my diagnostics of this starting problem.

Spraying starting fluid into the hard plastic black duct attached to the air intake allows the car to start and run briefly. It runs as long as I continue spraying the ether into the duct.

So that points to no fuel delivery. I cannot hear any noise from the fuel pump assembly when turning the key to accessories on, nor when cranking the engine. I am guessing then that either the fuel pump is gone or there is no power getting to the fuel pump.

Please advise how I can move forward from here.

Check fuse? (Where is it?)

Fuel pump relay? (Where is it? how could i test it?)

Bang on fuel tank from underneath with rubber mallet? (Don't bother?)

use multimeter on connections to fuel pump assembly to check for power? (Which wires/terminals? Are there only two?)



Something else? (Suggestions?)

I am not trying to be lazy here in asking for help from you good people, but I know someone here will have answers. I will try to find out answers to these questions but will take me some time.

Will a scan be likely to give any pointers at this stage?

Any help that you can afford me will, as always, be most gratefully received.

Thanks,

Paul

Fuse locationshttp://forum.a8parts.co.uk/attachmen...9&d=1308331472





There is a relay somewhere but not sure which one it is.

Fuel pump is on the right side in the boot. Lift the carpet and remove the metal cover. There are more wires there as you have wires for level sensor as well. I don't remember wire colours but it's fairly obvious which are for the pump as the sensor wires are smaller/thinner. You can test the voltage at these wires with mulitimeter or test light. Pump is powered only for a second or 2 when you switch on ignition, while starting and when engine is running so it's a 2 man job to test - one checking for power while the other switch on ignittion.

The relay is in the relay panel in the passenger footwell, in the bottom row. Not sure which one it is, but failure is rare compared to the pump itself. With the carpet up you should hear it click on and off when you turn the ignition on.

It probably is worth giving it a thump on the bottom of the tank to see if that does anything. Its not going to make it any worse ;)

Thanks very much for posting the decal as mine is missing when I just went to look

DARN! After double checking with ELSAWIN against the decal you posted it seems that someone has installed an incorrect fuse in position 1 of the blue(ST4) fuse carrier. The fuse is OK but it is 20A. Could that have led to the fuel pump burning out or something I wonder? Just off to check for power at the pump now :(

Found the relay - position 6. It clicks when ignition turns on and I can feel that with my finger.

No clicks from the pump or any other noise when ignition turned on or when cranking.

I have 12 volts at the fuel pump for a second or two when the ignition turns on. So that is shaping up to be more likely than not, a bad/stuck fuel pump.

What is there left for me to do?

I have read that I might be able to 'hot wire' the fuel pump and even perhaps reverse the polarity momentarily on the pump to shock it into life.


The car is parked across the road which is not ideal. I would really like/prefer to be able to drive it back on my lot so that I can repair it and it is not out in the elements. We have had bad hailstones here lately.

I am tempted to do something like this to get it across the road: :ROFL:

https://youtu.be/v3orW5pfODo?t=535

OR THIS?

https://youtu.be/vZxtDY1A9-Y

Doable?!

A pump in a jerrycan would work to move it, were it not for all the fittings in the fuel system. There's no point where you can easily attach a loose hose - it's a banjo in the back, a screw fitting at the front, banjos on both sides of the fuel filter.

Best way to move it I reckon is get some beers in to encourage a bunch of friends to push it for you :D

I'm sure we have a how-to for the fuel pump on here somewhere. Have a container in the boot with you to put the pump assembly in as soon as it comes out of the tank as it contains a couple of litres of fuel which will spill everywhere.

The original pump is a VDO unit part number 405052002001Z. Make sure the one you gett has two stubs on the bottom like this:
https://www.autopartsapi.com/eEuropa...54e64d9cef.jpg

There are many listings for pumps which are almost the same but missing that second little stub which is what drives the balance assembly for the two sides of the tank.

Thanks MikkiJayne.

That is the pump that I have in my cart on the FCPEuro website. VDO. Cheapest that I could find it listed for is USD $145.49, and I have bought from them before.

Good chance to buy a couple of oil fiters, air filters and perhaps the rubber seal for the fuel pump VAG-1J0919133A . <-- Is that worth getting? I already have a fuel filter kicking around I think. Bought a spare for my C4 A6 but I think it might fit the S8. Have to check the part number. Bosch iirc.

If I push the car, am I right in thinking that I won't be able to steer it very well and that the brakes won't work? It is a slight downward journey to the driveway then a sharp right and then a bit of an uphill push to the carport. How many 'friends' do you reckon it will take? +++ Thanks for the suggestion by the way.

Not sure about access around your carport, but it might be safer to tow it with a solid bar, as trying to stop a two ton car going downhill that has no brakes or steering may lose you a friend or two.

Brakes will work to hold / stop it in this kind of scenario. They'll just need more force on the pedal than normal. Ditto steering - it will be very heavy, but you can heave some lock on before pushing.

If its going up a slope then I would say at least four mates to push, and one to throw a brick under a wheel if they run out of steam! The other option is a ratchet strap tied to something solid to winch it up the driveway.

Get the tinnies in +++

The fuel pump was replaced when mine went bang last year but the seals were not. End result was as soon as I filled the tank up, a fair amount of fuel was dripping out from underneath the car. Looking in the boot under the access hatch, you could see petrol on top of the 'fuel delivery unit', along with the usual heady smell of Super Unleaded. Booked in at the garage and a new seal kit was fitted. The seal kit wasn't cheap.

I have seen that gasket set. I am extremely reluctant to buy it at $200.00 US That is $50 USD more than the pump!

I have ordered the pump, filter and the large gasket that I linked to earlier. I am going to cross my fingers that I can get the other o-rings locally and that the weird hexagon shaped gasket is in good shape...anyone else want to chime in with their experience with this gasket kit? 0_O :-(

Sadly, I can't tow it.

Thanks! Will do that!

I took my A6 Avant for a dry run into the drive tonight from a standing start parked next to the S8. It made it into the drive and most of the way up the drive under it's own inertia! I am going to have another go tomorrow with the A6 not started but ignition on and see if I can achieve similar results. I wonder if the S8 will perform similarly. I am a bit worried because of the reduced clearance under the car.

The gasket set for the pump seems to be very dependent on your local fuel quality. The Americans consider the tank seal essential, and seem to have lots of problems with the seals in the pump failing, but they have been absolutely fine in every UK car I've worked on. I've not had to replace the main tank seal either. It may be to do with the amount of ethanol in the fuel? I believe America has had ethanol in standard fuel for longer than we have.

One thing to mention - make sure you get two new banjo washers for the outlet on the pump (N0138128, 12x15.5x1.5) as they don't like being re-used and don't come with the pump. Ditto the filter - 2x N0138149 14x18x1.5 and 2 more N0138128.

Oh thank you very much indeed for that information. I am *guessing* that the previous owner only used RON 98 fuel (as have I) as he is so filthy rich, and would ONLY replace parts with genuine Audi ones. I might ask him though.

I hope that I already have a supply of the crush washers and will check against the ones that I take out, but thank you very much for posting their specifications! I take it that you have supplied dimensions in millimeters which I will compare to my stock. Thanks MikkiJayne!

Hi Paul,

Sorry I'm late to this discussion!

You can test the pump relatively easily.

Bentley describes a procedure to test it:
It says that fuel volume is measured at the fuel return hose under the bonnet...remove fuel pump fuse (#1 on row #4), ignition off, jump 12v to the lower socket of the empty fuse receptacle. You should get minimum of 350ml of fuel in 15 secs...anything above that, volume is good.

Ok - first of all, the fuel return hose - there are 3 separate hoses at a junction near the right hand (drivers side) shock tower (you'll need to remove the solid plastic inlet pipe to view them).
The hose you want is the tank return hose after the down stream side of the fuel pressure regulator. This hose is not under pressure and is safe to separate. Using this hose means you measure volume that the pump pushes under rail pressure (4 bar ~ 60psi) through the fuel pressure regulator. The area where the three hoses are all together should have a series of joiners for each hose with crimp joiners holding them in place. I cut through one of these crimps, separated the hose and used a 1 foot length of whatever hose I found in the garage (vacuum probably) and fed from the fuel rail side into a margarine container (600ml coke bottle or similar will do too, it won't be in it for long).

Next, you can do as Bentley suggests and hotwire the fuel pump fuse.
Alternatively, you can do what I did and hotwire the pump directly from the battery with a toggle switch, as it's all in the boot - remove boot carpet, open the pump inspection hatch, unplug pump/fuel sender plug. The pump power is the heavier gauge wires.
Power directly to pump, earth via a toggle switch - it's all spade connectors, so easy peasy with a crimp set!

With everything in place (you'll be in the boot, so wedge the margarine pot/coke bottle somewhere), flick the toggle switch and count 1001-1015!
If it works and is able to push 350ml or more past the fuel pressure regulator, the pump is fine.

My 2c on fuel pump replacement:

1. Never do the long bolt up too tight - this is critical. Overtightening of the long bolt will deform the plastic surrounding the captive nut at the bottom. The nut will come loose in the plastic, and good luck ever getting that bolt undone again!

It's easy to judge by feel, you can feel it compressing the rubber on the metal/rubber "arched window" gasket, then when it contacts the metal it goes hard. Stop tightening right there - DO NOT TORQUE IT DOWN!

2. Metal rubber gasket.
On my car, I replaced this and the o-ring. But the price on this little kit has gone up significantly since I did mine.
My philosophy is to always renew seals on items like this, but I have to say that the gasket on my car was in very good condition, and could probably have been reused.
One suggestion I have seen was to use a rubber rejuvenating product (one with plasticisers such as ATP AT205) to soak the seal in overnight to soften and rejuvenate the seal.

3. Removing and reinstalling the pump assembly:
I've watched videos and read people's accounts of removing and reinstalling this pump.
It has a narrow area in the tank, which the assembly has to pass through as it goes in and out of the tank. People push, and pull, and twist, and rip this assembly out of the tank.
This is completely unnecessary.
The pump is shaped like a step, and to remove it you simply pull upwards, and then twist it around gently while pulling and remove it like a corkscrew. I think its anti-clockwise out, clockwise in, and about 180° of motion, but don't quote me!
It will come out easily, and if it doesnt, you're doing it wrong.
Just note it's orientation when removing so you know where to reinsert it. Once seated back in the tank, there are two triangles to line up (one on the tank hole and one on the pump assemnly top) and it should go there easily without force.

4. Inner tank pump housing recepticle:
This is the large housing inside the tank with all the suction hoses coming off it.
It has a hook, which hangs off the tank filler tube at the top centre of the tank. It's a bit like a plastic coat hanger, but very heavy duty.
Pump removal can knock this hook off the filler tube. If it does, you'll never get the pump assembly seated properly.
It's pretty easy to feel inside the tank for the hook and make sure it's over the filler tube (the filler tube runs roughly horizontal across the top of the tank, and feeds directly into the fuel pump bowl once it's installed).

***Car is back on the road!***
 

Thanks to all of the wonderful posters here, I am delighted to say that my car is back on the road after I replaced the fuel pump. I don't recommend doing this yourself if you are rich enough to pay someone else to do it. :ROFL:

I sourced the VDO fuel pump form the USA for 145USD plus shipping to Australia. The cheapest that I could buy it locally for was 540AUD :tuttut:

I really appreciate all of the tips, help and advice that I received here in this community. It made my job a lot easier. This job was very fiddly and complicated. The 22 year old plastic housing scared me. At over one thousand dollars new, I knew that I had to be careful and probably lucky too.

I have assembled a document detailing my 'adventure' and am posting it here. It may be good for a laugh!

Attachment 23045

Thanks again!

Yay! :)

Triple yay from me. The documentation was an interesting read. I'm so pleased you got it sorted.

Nicely done! ++++++

I wouldn't have thought it necessary to "celebrate with several whiskeys" after sitting in the boot for hours getting high on petrol fumes. :D

After driving my S8 and guzzling 72.8 litres of fuel from the tank, I am happy to report that the car started more or less instantly each time, and was down to the reserve with the petrol bowser tell tale indicator showing in the cluster display when I finally filled up.

This indicates to me that I must have installed the fuel pump housing properly and that it is safe for me to assume that this particular repair measure is complete. The Audi documentation says that I should perform a certain fuel leak test on an empty tank, but I think that I can forgo this and just drive the car with confidence. Yes?


I'll second that! I am so relieved.

Glad you found the pdf interesting. The repair was an adventure for me and an exercise in patience! I am also very pleased to have fixed the problem with so little diagnostics.

Thank you, thank you! My sense of smell has suffered since the back seat of my C4 A6 Avant caught on fire during a road trip a couple of years ago. I had to drag the seat out of the car and put the fire out with a bottle of orange juice.

I think that lack of smell affected me psychologically when I did this job, because I could not really smell the petrol and so, did not get high on the fumes. (Kind of like the logic of the Ravenous Bugblatter Beast of Traal if you have read Douglas Adams) Consequently, I felt that I did need to celebrate with some whiskey!
Attachment 23071

I shall be sure to keep a towel on my head next time I do the job :ROFL:

:ROFL:

If you think of my username as initials you might notice it stands for something (something that equals 42). I've always been a big fan of Douglas Adams' work. +++

Well, well, well!

Meaning Of Life, The Universe And Everything. :ROFL: *=42 ASCII AKA anything/everything. I don't think that I realised that until tonight. Thanks for leading me to that. ++++++