No Fuel at the engine....

Paddys

Paddys

Member
My A2 is having a bad time of it. At the point when I was about to drive my A2 to it's MOT it refused to start. I had a mechanic come and have a look and he diagnosed an issue with the timing belt (it was shot). Having replaced that and the brakes which were also worn we put it all back together and it still doesn't start.

We are getting no error codes on a Diag box on start-up and all the readbacks seem normal. We have had the vacuum pump off the side of the engine and made sure that it is turning and that it is pumping when rotated however there doesn't seem to be much fuel being delivered.

At this point I am querying:

Fuel filter,
Fuel sender pump (the older 1.4 TDI does have one ?? - where is this fused ?)
A rather large airlock...

anyone got any experience in this kind of thing can provide any advice ?
 
A timing belt will only prevent an engine starting if it has slipped or if it has broken. If that happens then the valves are likely to be damaged at the very least.

So can you clarify how the belt was causing the problem? Just to help with determining what is wrong.

If it broke then you need to do a compression test to see if valves have been bent.
If it didn't break and was just worn/tired, the it was not contributing to the starting problems.

Steve B
 
So, the course of events:

1. Car wouldn't start and needed MOT.
2. Mechanic got the car started (needed quick start but then ran on its own on diesel - didn't test for long) and replaced brakes - car sounded rough so inspected the timing belt and found needed replacing.
3. Replaced timing belt (and found some other issues - air leak on turbo, turbo pin jammed etc) - timing was checked to ensure that it lined up with both new and previous timing marks.
4. Couldn't get the car to start except on quick start
5. checked vacuum fuel pump.

any more ideas ?
 
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when you turn the ignition on do you hear the fuel pump running for a short time pumping up the line presure, even when you turn ignition off and on youl hear the pump running for 5 seconds or so, which might show a posible fuel pump fault, you could also check fuel filter as this could be blocked , and only about £5 to replace, but just removing the filter from the bracket 1 hex screew and then the pipes would show if any gunge / grime by shaking it out, its under the heat sheild infront of the rear wheel. there is normally a fuel shut of valve on the diesel pump itself on diesels but unsure on the A2 one as never had a look at one.

Gary
 
A VCDS scan would surely show up some errors if the car is not starting?

What are you using to read the codes?.

Sounds like it could be a loose/damaged sensor connection or loose turbo pipe (one of the Small vacuum pipes possibly?)

But without any error codes it is difficult to help.

Best place to start looking is for the items that have been replaced, so around the turbo area and around the cambelt area, perhaps a connector has been damaged or is loose?

Steve B
 
JIGSAW said:
when you turn the ignition on do you hear the fuel pump running for a short time pumping up the line presure, even when you turn ignition off and on youl hear the pump running for 5 seconds or so, which might show a posible fuel pump fault, you could also check fuel filter as this could be blocked , and only about £5 to replace, but just removing the filter from the bracket 1 hex screew and then the pipes would show if any gunge / grime by shaking it out, its under the heat sheild infront of the rear wheel. there is normally a fuel shut of valve on the diesel pump itself on diesels but unsure on the A2 one as never had a look at one.

Gary
Click to expand...

Cheers Gary

I presume you mean the pump at the tank end rather than the vacuum pump ? I haven't heard anything which could mean this is the culprit - is this a free-flow pump (should you be able to manually pump through this). I will look into the fuel filter if it is only a £5 job.

PaddyS
 
My Mechanic has a little red box which he was using to scan the car - apparently designed for audi's. He's not getting any error codes on that at all. The turbo pipes have all been on and off so many times it would be difficult for any one to be the problem - we have double checked all of these as we've gone on.

I'm thinking it must be the secondary pump as we've double checked the vacuum pump :( Anyone got a spare ;)

P
 
Not sure if its free flow as such and you would hear it running when you turn ignition on as pumps up the fuel line preasure if you aint hearing anything id imagine this is your problem as the engines getting little or no fuel, lift up and remove your back seats, then remove the carpet / youl find a roundish black plastic cover , remove this and check the connections to the pump and fuel level sender incase its a bad conection ,i remember recently another member had a fuel level problem after having the pump replaced and posted a few pics.

Gary
 
I had already had a look at this. There only seem to be two electrical connections which are easily accessible and those transmit the fuel level (removed one to check and the level dropped).

I did try priming the system using a hand pump and noticed that the diesel is a mucky colour - guess I now know what at least part of the problem is. There is no pumping sound so I'm guessing I have had a batch of diesel which has jammed the pump / filter. Any thoughts on whether it will be a full replacement for both ? I am going to pump the tank out and flush with some clean fuel before going too much further...

n.b. The colour may be the result of the mechanic blowing through the fuel line to check there weren't any blockages and in doing so stirring up all the **** at the bottom of the tank!
 
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if the pump is not running when you turn the ignition on, then it could be a blown fuse or the pump itself has seized/brushes worn out. there should be a connector block ontop of the tank assembly with 4 or so wires for fuel level and pump power, id check fueses if none blown , remove pump and deassemble and get a small container and submerge the pump in petrol to clean it out as such, shake it about abit to get all the petrol gunge out ect, and then when it looks clean leave it to dry out fully, then plug it in out of the tank and turn the ignition on and see if it comes back to life, if not it will probally need a new pump, you could also use an electrical tester and check for power at the plug to see if the pump is getting power before dismantling it.. im unsure what outputs youl be getting but id earth to the battery as close and imagine with ignition on youl have 2 live wires ..

Gary

hears a few pics for ref;
http://www.ebay.co.uk/itm/AUDI-A2-2...ts=Car+Make:Audi|Model:A2&hash=item2ca08a6e78
 
Please be careful if testing the pump out of the car. Do it well away from the tank and only if it is completely dry.
Fuel fumes could be ignited when yo connect a live feed.

I I know you would do this anyway, but it never harms to be sure on safety.
Steve B
 
As a Chemist I know the hazards well but a reminder never hurts. Fortunately we're on diesel and not petrol making everything a bit easier and safer.

Does anyone know which fuze it is as the map I found on the internet suggested a fuze which doesn't even exist on mine.
 
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