car not starting, any help out there please?

hi all

i have an a4 1.9 tdi (110) 1996, AFN engine code with wastegated turbo. i had some recent power problems with the turbo not kicking in which was fixed by replacing a split hose. on my first test drive i got some black smoke but other than that and all seemed well but when i pushed it hard i lost most power! i limped home tried again the following morning and the car wouldn't start!

when i try to start the car the engine just spins and spins, there is absolutely no change in noise to indicate it may start. i had a recovery service come out and after a few elec tests he diagnosed a faulty diesel pump. great an £800 exchange part + fitting! when he left he told me he was not a diesel specialist which left me with some hope he may have got it wrong.......? i checked the troubleshooting & maintenance link on this forum and it say's that to diagnose a faulty pump is done with the engine running and diagnosis in vag-com. does this mean that the car would still start even if the pump is faulty? i pulled the pump relay out and this stopped the pump switching so it seems to be getting electric.

i have checked to see all the hoses are in place and they are, i've looked to replace relay 109 but i don't actually have one! i think this relates to my engine code???

vag-com scan is currently picking up no engine faults. the glow plug light on the dash board go off as it should.

i don't really know where to go from here? the advice of the faulty fuel pump was a shock as i would have thought the not starting is related to my turbo issues when i lost the power and barely got home?

i'm pretty desperate for some advise from someone that knows about diesels if anyone is kind enough to take the time so i can get back on the road. i'm worried as a faulty pump replacement would be hard to justify taking into account the mileage and age!
many thanks

In the US most of us would replace an IP if needed in a 96 B4. You do what you have to do. I understand that they are very common in the UK, but not here.

See if there is any fuel getting to the cylanders - crack open injector #3 when turning over to see if any diesel is there. If not, you have a real fueling problem - could be air in the lines, could be the IP. Generally, however, the IP makes a lot of noise if it's bad.

Another potential is that you slipped a tooth on the timing belt - so you are now way out of time. Look at the tb and surrounding items, and if all looks good, put everything to tdc and see if all lines up.

Is your intake clogged up with soot from the EGR thus starving the engine of air?

mogolf - does this happen with good fuel in the UK? I'd really like to know the answer to that.

thanks for the reply guys
i did check the intake and it seems fine, i thought this was most likely after my turbo issues, IP is not noisy at all.
i spent some time yesterday trying to fault find, turns out i'm not getting any fuel delivery to the fuel injection pump that was diagnosed faulty by the recovery man! i checked and changed the fuel filter which i read if blocked would cause problems but made no differece. i then disconnected the fuel line at the top of the engine and the line was dry inside. i turned the engine over while line disconnected and nothing come through. attention then went to the pump in the tank (accessed through the boot) no noise was coming from the pump when trying to start.
i'm not experienced in using an elec meter but tried to test the pump the best i could. i earthed the meter to ground and checked current on each of the 2 elec pump supply connections (there are 4 pins with 4 wires coming from the connection but only 2 terminals on the pump) i found one pin showing a reading of 6 volts but the other was dead. tests were the same while turning the engine over. i'm guessing this elec supply is the fault?
i run the meter across the 2 terminals on the pump and i was getting an ohm reading which was encouraging but am not sure what i am looking for to confirm that the pump is ok?
can i run a positive and negative feed to the pump direct from the battery to check that it is working ok or will this do any damage?
does anyone know how best to diagnose this pump or supply to it?
i guess the pump is relay controlled? if i know the pump is ok i will try and find out which relay and replace it before doing anything else. i thought vag-com would show faulty relay though?
thanks again for the help

In the US, the 96 B4's didn't have pumps in the tank - only the IP. I guess the 110 were different design.

thanks, i'm not sure if that part is actualy a pump now as i've read on a 2.5tdi it is a vacuum to get the fuel to the resevoir and the IP sucks the fuel from the resevoir? the part in the tank is part number 8d0 919 673 but i can't find nothing on it to find out what it does, there is 2 fuel lines coming from it and one electrical connection.
i guess i'll have to wait for a reply from someone that knows what it does but thanks for trying to help.

When you put the filter on, did you fill it with diesel? If not, do so. You can also pull a vacuum on the filter and draw the fuel in from the tank. Then crack one fuel line at a time, with a rag around it to catch the fuel, while cranking.

Good luck,

Roger

In NA cars, there should be a supply and return fuel line, and an electrical connection for the fuel gauge at the pickup for the tank.

You really need to attach a vacuum pump to the supply line, and pull a vacuum to draw fuel to the filter. Is this easy to do? If not, check for damaged/crimped fuel lines, expecially in areas where it runs through the bodywork. Remove the pickup from the tank, occlude the pickup, and pull a vacuum. Are you pulling air? If so, find where the air is coming in.

i did fill the new fuel filter with diesel when replacing.
i will try and source a vacuum pump and draw fuel from the tank, all the lines seem clear on visial expection.

so the lift pump on the tank is totally silent in operation and the electrical connection on it is only to read the fuel gauge? can you confirm this?
how far down the fuel lines does the fuel need to be before the injection pump can suck?
maybe my injection pump needs replacing after all???? ouch!

Someone at some point in the history of this car has put a petrol pump into the tank. '673' for the last digits indicate the petrol pump. The diesel fuel pick up would have '183'. Is this a Golf, Vento or Passat? Sedan or Estate?

Since you have a petrol pump in there, you could have a clog at the pickup. I suggest removing it and checking for a restriction.

car is an audi a4 - audi have confirmed the same part number as the diesel pump for the replacement from my chassis number.

the rear lift pump on top of the fuel tank electrical connections are for the fuel gauge. can anyone explain how this lift pump works? is it some kind of vacuum and can they go wrong? does the front pump activate the rear lift or is the rear lift pumps job to get the fuel to a certain point where the front pump can suck?

thanks

Ok. Sorry but just saying 'A4' here usually means the VW A4 platform.

Yes that number is a fuel gauge sender and pickup on a 1996 Audi A4, and it is not a lift pump. There is no pump motor there to hear thus the silence. The only fuel pump on the car is the one on the engine.

So the next test is a hand vacuum through the line to the filter. If you can draw fuel by hand, then the injection pump is suspect.

sorry for the confusion, i didn't realise.

trying to start update........
on taking some advise i cleared the fuel line from the fuel tank all the way to the fuel filter and re syphoned the fuel feed through. i topped up the fuel filter with diesel and loosened the injector feed on the 2 centre cylinders. trying to start i'm getting some fuel to the opened cylinders but not as much as i was expecting. i would estimate that the fuel splashes up around 2-3" on both of the open cylinders, i was expecting a lot more than that. i was also getting a lot of white smoke from the exhaust.
any suggestions where i go from here? should the fuel be coming through quicker? does this mean it's the injector pump that is faulty as diagnosed by the recovery man?
any suggestions of what i could try are greatly appreciated. i've even had the immoboliser suggested, does this make sense? any further tests i can run?
thanks for the help

The next step is to verify the physical timing of the cam, crank and pump. When the cam is locked (as if doing a timing belt replacement), the crank is at TDC mark, and the pump can be pinned in locking position. Also verify belt tension.

worn bottom timing Sprocket

take your bottom timing belt cog off its probably worn and the crank too in the afn engine a short half moon shape