Audi 2.5tdi no start

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audi5inline

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I have a problem with the a4 b6 q 2.5tdi BDH from my brother.

The tensioner on the fuel injection pump failed and due to this the belt sheard off a couple of tooth, the car did run but very rough, so i think it also slipped a tooth.

I ordered a new tensioner and belt and fitted them,
checked the timing and timed everything by inserting the crank locking pin and the locking pin for the fuel injection pump.
I had disconnected the fuel lines on the back of the fuel injection pump so i bled the system with a hand vacuum pump on the fuel return line at the fuel injection pump. after that i unscrewed all the injector lines on the injectors and cranked the engine and fuel spitted out of the lines so there is fuel at the injectors.

But no start after this...?
when i try some brake cleaner in the inlet it will fire with only for one seconds
i scanned the car and no codes come up
 
Sounds like you have timed everything correctly if you have used the correct locking pins. Not sure why you disconnected the pipes from the pump but I assume they are all back in the correct order. If that is the case and there are no fault codes then it can really only be air in the system. These are hard to bleed and take some cranking to get all the air through. Slacken the nuts on the injectors a small bit and turn it over until the engine starts to catch. Only slacken a bit or you wont get enough fuel through to the injector. Use plenty of old rags or the diesel spray will destroy the engine bay.
 
thanks for the help, i just tryed it with loosening the injectors only a little bit and tryed starting it until the battery went low, i think 2 minutes but no couging what so ever...

i dont know if its possible but i also tryed turning the pump 1 full turn, because it turns twice with every crank rotation if im right. but still no luck. i used all the correct locking tools.

and a quick scan with vagcom but still no codes...
 
maybe i have a bleeding problem after all. i replaced the copre rings on the injection pump and after that i wanted to bleed the system again. but i dont seem to get the air out, am i missing something ?

 
Double check timing. Crank locking pin should be fully located and OT visible on the cam with the oil filler cap removed. Engine is now at TDC. Locking pin should slot in to the hole in the pump. If this is all good then remove locking tools and bleed the system. I have never used a vacuum pump but the following has always worked for me.
1. Refit all diesel feed and return pipes. Check pipes for splits or loose connections.
2. Slacken small bleed bolt on filter and turn the starter just a quick turn. This activates the lift pump and you should get a strong spurt of diesel from the filter with no air bubbles. If there is air then repeat until it clears.
3. Remove the flow pipe to the injection pump from the filter end. Fill this with clean diesel using a small funnel or similar. try and hold it up to allow all air bubbles to clear from the clear line. Once full try and reattach to the filter without letting any air into the pipe. A tiny bit won't matter.
4. Make sure all pipes are tight and now slacken a few injector pipes. Usually 2 or 3 will do. Slacken just a bit not too much. Use rags to catch any spray from the injector pipes and crank the engine. You should see air bubbles and diesel spray out of the injector and the engine should start to catch or start. It will usually take a bit of cranking.
5. Tighten pipes and it should be ready to run.

Fingers crossed!
 
still nothing.... , tryed all the bleeding technics i know but still not a single burp. can something in the pump fail because of running dry ? a diaphram or something
 
Any fault codes? These pumps are notorious for giving trouble but they usually throw a fault code of some kind. Are you getting diesel to the filter?
 
yes fuel is getting to the filter, i put 12v on fuse 28 and fuel will come out the bleedscrew on the filter when i do, i can also hear the pump in the tank run. tryed starting it with a coke bottle full of diesel upside down connected to the suply line on the filter but with no luck. still no fault codes.
 
Is there diesel in the clear line going to the pump and no big bubbles of air? Are you getting a good spray of fuel from the injector pipes? Also if this is a manual you could try tow starting it as there are some engines very stubborn to bleed that only towing will clear.
 
it seems that the clear line is full of diesel, but some times i see a air bubble on the top op the line, also when i manually fill that line with diesel and after some cranking i sometimes see a air bubble in the line, maybe air is coming back up from the pump ?
 
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Is it a manual to try tow starting? That bubble still suggests air in the system but I see a good spray from the injectors so I would have expected it to show signs of starting. The ecu on these pumps can fail without warning and can screw up the pump timing so even though you get diesel at the injectors it may be being pumped at the wrong time , hence no starting. They normally generate fault codes though. Maybe adamss24 will see this and offer some advice as he is brilliant on these engines.
 
audi upgrades
audi5inline said:
still nothing.... , tryed all the bleeding technics i know but still not a single burp. can something in the pump fail because of running dry ? a diaphram or something
Click to expand...
Pump is dead... It needs a rebuild...
 
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