Intake cleaned / NO start / Bleeding Fuel--unsuccessfully

Please help, I’m stuck as to what to do to start my 2001 Jetta TDI with 365,000 miles.
Previously I had NO problems starting the car AT ALL. I cleaned the EGR and intake, and when I went to start car afterwards it would crank but not turn over (never did start even briefly).
More info:
I went through a list on this site of all things to check that would cause a no start (short of using Vag-Com--Got one but having problems downloading the driver). Everything else checks out ok, and what I’m down to is air in the line. I know there wasn’t any fuel in the clear line from fuel filter to IP. Tried cracking injector nuts but didn’t get to any fuel coming out while cranking engine). I’m thinking I have a leak, but where??
I’m using MityVac to help with my no start issue. Not having luck, OR maybe not doing something right. First please advise on MityVac use—I’m a first timer with it:
a. I’m unsure of how many Hg to pump MityVac up to. I have not gone over 15Hg. What’s suggested for bleeding the fuel line?
b. Will pressure on gauge fluctuate while doing this procedure, because it is not holding.
So with the MityVac I have done the following:
1) Pulled fuel through from tank by putting MityVac at the hose that brings fuel into the fuel filter. I filled up the little MityVac cup 4-5 times before air was gone, but the air did clear out. Reconnected.
2) Then I put MityVac on the hose end that attaches to the IP (from the fuel filter). Was able to pull fuel until no air bubbles here also. (Once disconnected from MityVac the air went back in the line.) Reconnected.
3) Pulled IP return line off the fuel filter where it attaches to the T and attached MityVac there. I’ve been pumping on that for a loooong time, and air bubbles just keep coming, lots. Sometimes 1/3-1/2 of the clear line is taken up by small bubbles. It takes a long time to fill up the tiny MityVac cup because there’s so much air. I think I’ve pulled almost ½ gallon of fuel out so far. I’m under the impression that I should be able to get the air out at this location, and THEN crank car and crack the injector nuts to bleed. Is that right? OR do I first crack injector nuts to bleed and THEN put MityVac on this location?
4) OR does this mean I have a leak from just before the IP, back to the fuel filter? I don’t see any wet areas around the injector lines, return lines or IP. I did not previously smell any fuel in the engine compartment. The fuel return lines have always been gunky because I previously had an oil leak that splattered everywhere, so I can’t tell for sure if they may have a small leak.
Am I right thinking all this air in the #3 location is suspect? Or do I just keep on pulling fuel thru until I *eventually* get no air bubbles?
AND while I’m asking questions…
aa) When I do go about cracking injector nuts, what’s best? One at a time? All four at once? (I’ve heard only ½ turn is necessary). If one at a time, which one first? (And which is #1, on passenger or driver side?)
bb) If I go ahead and replace fuel return lines, where can I find what size I need and is this something I can just pick up at parts store or should I get from dealer? I don't have time to order online and wait for delivery.
I can't see that anything I did during intake cleaning (it was removed to clean it by the way) would cause me to have air in the fuel lines to prevent start up. But I’m short so I was sitting on top of engine compartment (mostly all on drivers side) on padding while working. Could I have compromised something? Could be coincidental, if so it reflects my luck. Car has been down over a week now--I need it bad. Any help appreciated!

At 3 you sucked on the return line from the pump. Did you plug the nipple on the tee while doing this? Should have if you didn't.

I'd pull the small line from the nipple the injector return lines connects to and suck there. You won't get much flow once fuel reaches the pump.

#1 Is the cylinder nearest the belt.

KLXD said:

At 3 you sucked on the return line from the pump. Did you plug the nipple on the tee while doing this? Should have if you didn't.

I'd pull the small line from the nipple the injector return lines connects to and suck there. You won't get much flow once fuel reaches the pump.

#1 Is the cylinder nearest the belt.

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I did NOT plug the nipple on the T (good point!)--I will go ahead and try that since I left everything hooked up as in #3 above.

If needed I'll also pull that small return line where it goes to the IP. I didn't try that one because the lines are so old I figured I'd ruin the seal and have to replace...but I guess I might as well replace all those return lines considering age/mileage. Just have to find out what size exactly and best brand and source.

THANK YOU!!

AND I finally got the VCDS drivers to install on my computer, so VagCom will be usable, will read up on instructions and maybe see if there's any good instructional videos on YouTube.

In addition check the vacuum lines CAREFULLY since you had the intake off and thus had to disconnect them. It's entirely possible to put the wrong hose back on the ASV....

Genesis said:

In addition check the vacuum lines CAREFULLY since you had the intake off and thus had to disconnect them. It's entirely possible to put the wrong hose back on the ASV....

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Ok will do. l was trying to be very careful with them, and l replaced all the vacuum lines afterwards, but l’ll look for a picture to double check for correct one on ASV.
THANK YOU!

When you pull vacuum on the fuel system you MUST plug the other open end you create (otherwise air will enter THERE!) I have a little 12V fuel pump that works better since it provides pressure instead; I insert it BEFORE the fuel filter (so there's no unfiltered junk that gets into the pump or injectors), it has alligator clips on long wires that I then connect to the battery. It runs until pressure is built, then stops. I put that on and let it run, crack #3 injector (it has the needle lift sensor), crank until I get fuel there (which doesn't take long; wrap it with a towel or it will make a HUGE mess!) and then snug it back up and it should start.

If you're using vacuum then the proper path is to (1) remove the feed from the filter to the IP at the filter, PLUG THE HOSE GOING TO THE IP and draw vacuum through the filter until you have clean fuel (no air), (2) remove the RETURN line from the IP to the T, PLUG THE T, and draw vacuum until you have clean fuel coming THROUGH the IP. This may take a while and the fuel return, when you get it, will be VERY slow (almost none!)

Then reconnect the fuel lines, crack #3, wrap with a towel and crank until you get fuel (should only take a few seconds; if it takes more than 10-20 seconds SOMETHING IS WRONG; you didn't get the air out!)

Then snug it up and it should start, assuming of course that you have the vacuum hoses in the right place (as I noted, if you put the wrong one on the ASV it'll be immediately closed which will definitely hose you!)

Genesis said:

When you pull vacuum on the fuel system you MUST plug the other open end you create (otherwise air will enter THERE!) I have a little 12V fuel pump that works better since it provides pressure instead; I insert it BEFORE the fuel filter (so there's no unfiltered junk that gets into the pump or injectors), it has alligator clips on long wires that I then connect to the battery. It runs until pressure is built, then stops. I put that on and let it run, crack #3 injector (it has the needle lift sensor), crank until I get fuel there (which doesn't take long; wrap it with a towel or it will make a HUGE mess!) and then snug it back up and it should start.

If you're using vacuum then the proper path is to (1) remove the feed from the filter to the IP at the filter, PLUG THE HOSE GOING TO THE IP and draw vacuum through the filter until you have clean fuel (no air), (2) remove the RETURN line from the IP to the T, PLUG THE T, and draw vacuum until you have clean fuel coming THROUGH the IP. This may take a while and the fuel return, when you get it, will be VERY slow (almost none!)

Then reconnect the fuel lines, crack #3, wrap with a towel and crank until you get fuel (should only take a few seconds; if it takes more than 10-20 seconds SOMETHING IS WRONG; you didn't get the air out!)

Then snug it up and it should start, assuming of course that you have the vacuum hoses in the right place (as I noted, if you put the wrong one on the ASV it'll be immediately closed which will definitely hose you!)

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OK, on the vacuum method, you wrote "Then reconnect the fuel lineS (plural), crack #3..." So that means that after I've done (1), I do NOT replace the hose, keep the HOSE PLUGGED GOING TO IP, and proceed to (2). After I'm done with (2) I THEN reconnect both lines. Correct? That seems to me that I wouldn't get any flow through on (2), but then that's probably why you said it would take a while and fuel return would be slow and almost none. Just want to be sure I'm understanding correctly.

Also, is there any limit to the amount of Hg I'm going up to on the vacuum gauge?

THANK YOU!!

No -- pull vacuum on the filter with the hose going to the IP plugged. Once you have clean fuel (no air), remove plug in hose, REPLACE hose to IP on the filter outlet, remove hose at Thermal "T" from the IP return and plug the now-open inlet to the T, apply vacuum at THAT hose (from the IP return) until you have fuel and no air at that point. Then remove the plug from the "T", reattach the hose to the "T" and proceed to crack #3 and crank (with a rag wrapped around it) until you have fuel there. Again, that should take only a few seconds (it helps to have someone assisting you who can tell you when the rag you wrapped on the nut starts to get fuel all over it.)

Snug up that line nut at the injector and it should start. It may fire intermittently for a few seconds and run quite roughly for a few seconds more as air is expelled from the remaining injectors, but it should start.

Some people crack ALL the hard lines at the injectors and wrap them all with rags but I've never needed to do that; once I've gotten one cylinder to fire the additional cranking speed from that is enough to clear a second line with a few seconds, it fires, etc.

One reason that I prefer the pump solution for this over drawing vacuum is that there is a very real risk of getting dust or other debris into the line *after* the filter. You have to be VERY careful not to allow that to happen (including when plugging the line with whatever you use) as there is zero real protection downstream of the filter and even a small amount of contamination can do severe damage to the pump or injectors. With the inline pump there's no risk of this since the pump is in front of the filter, and all fuel that passes from that point onward is clean.

You shouldn't need to draw more than 15" or so of vacuum on the pump but there's no harm in drawing it down by more; it won't speed it up that much on the return side (the tolerances are quite tight in the pump and once you actually start pulling fuel through it will take a little bit to fill the lines to the injectors.) There's only ~30" of vacuum (1 ATA) possible, after all. On the filter if you can actually manage to generate more than a few inches of vacuum using a Mityvac something is obstructing the fuel feed line or the filter is (badly) plugged.

Genesis said:

No -- pull vacuum on the filter with the hose going to the IP plugged. Once you have clean fuel (no air), remove plug in hose, REPLACE hose to IP on the filter outlet, remove hose at Thermal "T" from the IP return and plug the now-open inlet to the T, apply vacuum at THAT hose (from the IP return) until you have fuel and no air at that point. Then remove the plug from the "T", reattach the hose to the "T" and proceed to crack #3 and crank (with a rag wrapped around it) until you have fuel there. Again, that should take only a few seconds (it helps to have someone assisting you who can tell you when the rag you wrapped on the nut starts to get fuel all over it.)

Snug up that line nut at the injector and it should start. It may fire intermittently for a few seconds and run quite roughly for a few seconds more as air is expelled from the remaining injectors, but it should start.

Some people crack ALL the hard lines at the injectors and wrap them all with rags but I've never needed to do that; once I've gotten one cylinder to fire the additional cranking speed from that is enough to clear a second line with a few seconds, it fires, etc.

One reason that I prefer the pump solution for this over drawing vacuum is that there is a very real risk of getting dust or other debris into the line *after* the filter. You have to be VERY careful not to allow that to happen (including when plugging the line with whatever you use) as there is zero real protection downstream of the filter and even a small amount of contamination can do severe damage to the pump or injectors. With the inline pump there's no risk of this since the pump is in front of the filter, and all fuel that passes from that point onward is clean.

You shouldn't need to draw more than 15" or so of vacuum on the pump but there's no harm in drawing it down by more; it won't speed it up that much on the return side (the tolerances are quite tight in the pump and once you actually start pulling fuel through it will take a little bit to fill the lines to the injectors.) There's only ~30" of vacuum (1 ATA) possible, after all. On the filter if you can actually manage to generate more than a few inches of vacuum using a Mityvac something is obstructing the fuel feed line or the filter is (badly) plugged.

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OK thanks, glad I asked. Thank you for such a quick response!!
I'm doing (2) now. T is plugged. (1) is reattached.
Barely any fuel but tons of air bubbles and the MityVac does not stay at 15...it loses vacuum. As I mentioned this is first time I've used a MityVac.
**Is it normal for the dial to go back down after I pump it up to 15? Or does that mean there's a leak?
(Someone was helping the other day and had all 4 injector lines opened about 2-3 turns each, so perhaps all injector lines/IP/and return lines are full of air?)

Think I'm calling it!! I've been doing the vacuum at IP return before fuel filter (with T plugged) for 2 hours now, still getting the same amount of bubbles, have pulled 1/2 gallon, and the dial on MityVac continues to drop after I pump it, leading me to believe I have a leak somewhere in the area before the IP and back to the fuel filter.
I'm just gonna replace all the return lines, as they've never been replaced, and try this again.

Probably. But I bet if you crack the line nut on injector #3 and crank until you have fuel, then snug it up the engine lights up at this point.

You should replace those small return lines anyway; if they're original they're almost-certainly rotted.

If you are flowing fuel or air into the Mitey Vac the vacuum reading will drop. That's to be expected.

A return line leaking/cracked will have no effect on the car starting. A blocked return can cause basically the same thing as a run away, but thats definitely not your problem. The return does just what it sounds like, returns excess, unburned diesel back to the fuel tank. I see you're new to these car's, and will tell you for future reference, there is no need to touch fuel lines for intake cleaning/removal. The vac pump is not going to hold if it's pulling fuel. If this were me, put everything together, leave #1 and #3 injector lines loose at the injectors. Crank until good fuel is flowing. Tighten them up, loosen the other 2 lines at the injectors, and repeat. I'd just about bet it will fire up. You will need to be able to tighten the lines with the engine running.

KLXD said:

If you are flowing fuel or air into the Mitey Vac the vacuum reading will drop. That's to be expected.

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Great! Thanks for clearing that up for me.

ghohouston said:

A return line leaking/cracked will have no effect on the car starting. A blocked return can cause basically the same thing as a run away, but thats definitely not your problem. The return does just what it sounds like, returns excess, unburned diesel back to the fuel tank. I see you're new to these car's, and will tell you for future reference, there is no need to touch fuel lines for intake cleaning/removal. The vac pump is not going to hold if it's pulling fuel. If this were me, put everything together, leave #1 and #3 injector lines loose at the injectors. Crank until good fuel is flowing. Tighten them up, loosen the other 2 lines at the injectors, and repeat. I'd just about bet it will fire up. You will need to be able to tighten the lines with the engine running.

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Well I did nothing to the fuel lines at all when I removed and cleaned the intake. That's why I was so confused that the car wouldn't start afterwards, and that I didn't have any fuel in the clear line from the filter to the IP. Makes no sense. But reading posts on this forum I see that a lot of people have no start issues after cleaning intake. I'm pretty sure my vacuum hose from ASV is hooked up correctly. To do it differently would really stretch the hose. And my ASV is open when car is off and when cranking.

What I wish I knew is WHY did my fuel run back into the tank, can only think that it's a leak somewhere, but I don't see one.

Well I removed return fuel line to replace them anyway...and my Repair Manual nor Dealer could tell me what ID I need. So I cut line to compare it to some vacuum hose sizes I have and it looks to be 5/32" ID. Unfortunately, none of the auto parts stores carry this size, and Dealer parts dept doesn't carry fuel or vacuum hoses at all. So now I'm down until I can find a place online and wait for delivery. (LOL, I just wanna be able to go home! Came to MO to borrow a shop to do intake, I live in KS)

THANKS FOR YOUR INFO!

I'm just hoping that once I get it started that the fuel doesn't drain back into the tank again and leave me stranded somewhere else.

I would look in the clear fuel line running from the fuel filter to the injection pump ever time the car sits for a few hours to see if you have a small air bubble.
Mine has one 1/2 inch or so.
If you see a longer one (judgement call) you probably have an air leak somewhere.
At some point you will get tired of checking it, I did.

wonneber said:

I would look in the clear fuel line running from the fuel filter to the injection pump ever time the car sits for a few hours to see if you have a small air bubble.
Mine has one 1/2 inch or so.
If you see a longer one (judgement call) you probably have an air leak somewhere.
At some point you will get tired of checking it, I did.

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I've been watching it. It was empty (for some reason) after I cleaned intake and it wouldn't start. I've used a MityVac to pull fuel after IP. The clear line filled up, but I kept getting lots of bubbles so I kept up the vacuum. THEN a bubble came back into the clear line. Eventually (I was trying to clear bubbles out of IP exit for 2 hours), almost the whole clear line was air again.
I'm stumped! I'm replacing return lines (just as a guess, and they're very old anyway), then I'll use MityVac again (not no 2 hrs again though!) and just try cracking the injector lines again and see if it will start. But now I have to wait for fuel line to arrive.

I've always had a small bubble in my hose when I shut down.
It's when it gets longer you have to worry.
Keep the M-Vac in the car with a wrench for the injector lines just in case.

What was the weather like before you started this work, when the car was starting just fine? And now?

Either something got disturbed when doing your intake work or you've got a coincidence.

Hook up a separate contained of fuel and pull fuel from it (and run the returns lines to it as well- be sure that the lines won't pop out of the container- I've had that experience and it ain't pretty). That'll say whether there's a problem before the IP or if it's the IP.

Finally! Got car started!
I didn't like the way the air kept on coming through with Mvac and the Mvac lost pressure so fast when I was drawing it through just before the Thermo T (with T blocked). Made me believe there was an air leak somewhere.
Anyway, I replaced all the fuel return lines.
Also, I went ahead and replaced the Thermo T, seeing many posts that one with a leak keeps car from starting. (Course could just be leaking air because of seals, but this T has been around for 365k, figured I'd be proactive and change it. And when I pulled the old one the seals (which were just replaced with new the fuel filter, looked fine, don't think they were compromised).
After those 2 things were done I again went through the fuel bleed process. This time when I was at the T, there were minimal bubbles, and the pressure on Mvac was holding much better, went down very slowly, and fuel very slowly filled cup.
This was promising!
Sealed that back up and cracked one injector. Cranked engine 10sec and got that one injector tightened, stopped cranking.
Cracked another injector, cranked engine, and it started! Whew!!!
It didn't even run roughly! SO relieved.
Tomorrow I will put VagCom on, adjust IQ which I had changed when driving with clogged intake, and check timing for good measure. Then I'll drive and turn off car on and off tomorrow to see if fuel might drain back to tank again, but I'm feeling pretty good about it right now.
THANKS to everyone who chimed in to help me along the way with this! You all rock!

Yay! Always a big relief to get over a hurdle (I've got a handful of them on my plate, though none involve these trusty ALHs).