2002 golf tdi Alh won’t start

Hey guys so I have a 02 golf manual Alh tdi , it sat in the cold over night with a glowplug issue , the starter went (I could hear it acting up ) pulled the car in and took off the stater, luckily I had a spare and bench tested both , mine was not engaging the solenoid so I put in my newer one

After I turned the key and it started up , but I was in my garage with the door closed so I shut it off after about 20 second max, after I rolled it out and tried to start it up again to let it run , No start, I thought battery so I boosted it had good lights on dash tried again no start. Pulled it back in check for air in the fuel lines and there’s about a two inch long gap in the clear fuel line from the fuel filter to injection pump. So I thought bingo that’s my issue , picked up a handheld vacuum pump thing , and continued onto bleeding it from that Little valve at the return line ( I watched a few videos to make sure I bleed the right spot )
So while I’m doing this the two inch long airline isn’t going away but I’m still drawing deisel into the container, with big bubbles at first and then proceeds to just constant mini tiny bubbles. If I tap the two inch long air gap in my line ALOT more bubbles come out , do I have a faulty injection pump or maybe some leaks somewhere ? I don’t seem to have any deisel coming out from anywhere, it’s dry. I’m not sure what to do next I’ve researched the common threads if it won’t start but can’t narrownit down and don’t want to keep attempting to turn the key
I have a Parts car with a seeized motor and another motor blown from my other car , so I have spare parts I just don’t want to bring it to a shop me and my friend have swapped this motor when my first one blew , that was 200xxx kms ago because of a faulty belt, so we can usually figure things out but this one has us stumped. Any help would be very appreciated.
Thanks guys

Are you saying you bled from the small barb on the return line? And the return line was still intact from the injection pump to the filter/thermo-tee? If so, what you were probably doing was sucking air from around the thermo-tee into the return line and into your vacuum pump's reservoir.

I had a car sit for too long, lose prime, and I wasn't able to purge the air from the pump until I finally plugged the small barb while applying vacuum to the return line tube (the one that returns fuel to the filter/thermo-tee).

If the small barb is left intact, it is likely that you will suck air from the injector(s) through the injector return lines and into your vacuum pump.

So, to purge the air, pull the line that returns fuel to the filter, and pull the injector return line on that small barb, and then apply vacuum to the large return line while blocking the small injector return line barb.

And with your 4th hand, you...



Cheers,

PH

Thanks power hound , I’ll try that and see if that works , I’m pretty sure I understand what your saying, seems straightforward . I’ll give it a try and post a reply
Thanks in advance
Cheers

Powder **

To add things that I tried btw
I replaced the 109 relay with the one from the Parts car, which didn’t make a difference, still waiting to get home to try what powder_hound recommends
Incase this helps for future reference

Did you crack open the injection lines at the injectors and get good air from them? Did you check the ASV? Did you check for voltage at the shut off solenoid for a few seconds day after key on? Did you check for RPMs on the tach? Did you check the timing belt timing? (BTW, timing belts are almost never "faulty" - unless bought from Prothe. Typically they fail due to something else failing.)

Checked ASV it’s working good , and by faulty I meant one that snapped because it was like 2 weeks into me owning my first tdi and didn’t know , it snapped on the highway and blew my motor , my fault obviously but yea anyways thank you I will also check those few things one by one and reply , timing belt looks good still it’s due and I was supposed to bring it in yesterday to my guy but iota now I’m this stage, I wanna check the rmps like you said. Thank you

Powder_hound, I just attempted to bleed it while blocking off that smaller valve from the pump and bleeding it from the line connecting back Into the fuel filter , still can’t get that big air bubble to move out enough to be bled through the injection pump ..

I just did the bleed once more and I got zero to no bubbles gave it a start , no start , checked the lines and the big two inch air bubble has returned in the clear line , I also hear a hissing sound coming come the little nipple where the fuel retun line is going back Into the fuel filter , ordering new fuel filter tonight since I predict that’s the problem along with lines since the one on my Parts car look pretty ****ty. Will update tomorrow

maxmoo said:

I am going to repost this reply again seeing as it may very well apply to this thread too.

"Sounds like your problem may be....

If it is fuel gelling it won't be in the engine, it will be in the fuel filter or at the sending unit/pickup in your tank.
Your sending unit/fuel pick-up, that is in your fuel tank, has a very small orifice at a check valve that can and often will bridge/plug with debris, ice, and/or gelled fuel.
When this happens the vacuum created by the inj pump trying to suck fuel will cause air to be sucked into the fuel system at the weakest link, usualy the thermo T at the filter. This all happens more commonly in cold temps.
See....
https://www.youtube.com/watch?v=yRMTEAKsScE
If this is your problem search "ALH TDI blocked check valve in sending unit".
The check valve can be drilled out and removed."

Click to expand...

.....

maxmoo said:

"Sounds like your problem may be....

If it is fuel gelling it won't be in the engine, it will be in the fuel filter or at the sending unit/pickup in your tank.
Your sending unit/fuel pick-up, that is in your fuel tank, has a very small orifice at a check valve that can and often will bridge/plug with debris, ice, and/or gelled fuel.
When this happens the vacuum created by the inj pump trying to suck fuel will cause air to be sucked into the fuel system at the weakest link, usualy the thermo T at the filter. This all happens more commonly in cold temps.
See....
https://www.youtube.com/watch?v=yRMTEAKsScE
If this is your problem search "ALH TDI blocked check valve in sending unit".
The check valve can be drilled out and removed."

Click to expand...

thanks a lot for your advice and for the youtube video. i'm having a similar problem to OP and that's why i'm searching for answers. gonna try it and see if it works. OP, please come back with updates on telling what you've done to make it start working. thanks again.

If you have a VAGCOM I would check to see if any codes are pending or posted. I have had a few no starts, one was a bad IP, a broken connector, and another I had to crack injector lines while trying to crank in order to clear last little bit of air then it started.

Replaced the fuel filter , still getting no start and air in the lines when I’m bleeding it , I’m ganna see the video of what maxmoo said and possibly attempt that , at this point I might bring it to the guy who’s supposed to do my timing belt and see what he things, I really need to get it going I have work and school everyday with a big commute

And no pending codes , did the glow plugs and those codes are gone

I’m not getting any restriction like the YouTube video mines flying (using the mityvac, for anyone who somewhat does there own work I’d highly recommend it)

Still stumped

Okay so I might have found the problem but I’m not sure , when I mityvac the peice from the fuel filter coming out going to the injection pump (I’m on the fuel filter though) I get a steady stream but with ALOT of medium sized bubbles getting sucked out indicating a clear leak of air and I pumped till I filled up my mini container, same thing throughout the whole cycle. I just replaced the fuel filter though, along with the two new oring for the peice that clicks into it(forget the name), and when I pull out of the line leading into the tank I don’t get any air bubbles
I know I tightened the bottom drain on the new one firmly and it’s not leaking , so where is my issue ?

Have you bled the lines going to the injectors as well as the pump?
Crack all four 17mm nuts and crank the engine over until you get fuel without air bubbles at all four injectors, then tighten down the nuts and try starting.

BoogsTDI said:

Okay so I might have found the problem but I’m not sure , when I mityvac the peice from the fuel filter coming out going to the injection pump (I’m on the fuel filter though) I get a steady stream but with ALOT of medium sized bubbles getting sucked out indicating a clear leak of air and I pumped till I filled up my mini container, same thing throughout the whole cycle. I just replaced the fuel filter though, along with the two new oring for the peice that clicks into it(forget the name), and when I pull out of the line leading into the tank I don’t get any air bubbles
I know I tightened the bottom drain on the new one firmly and it’s not leaking , so where is my issue ?

Click to expand...

You should be sucking from the return line going to the inj pump, but you must block off the line at the filter while doing this or you will simply suck more air in there....just put your finger over it while drawing a vacuum at the return line going to the pump until you get fuel only.
Then bleed the inj lines as I mention previously ....then start it.
good luck.

btw...I assume you fixed the glow plug issue?