Problem while priming fuel on my alh

[Alec2003]

As soon as I let go the succion, the fuel travels back in the fuel filter. I must be real dumb. Any help would be appreciated

 

[Marc Bourget]

Same issue, but I went "Duh !!" and realized the filler cap was still on (creating a vacuum?) removing the cap didn't help, problem repeated and, considering the thought, the small amount of fuel I drew to take the bubbles out of the line from the filter to the pump wouldn't create such a vacuum so I now wonder if the fuel canister (no lift pump) must have a type of check valve?

 

[Alec2003]

Not sure but I think there's a check valve inside the hpfp, thats why when I bleed from the pump the problem seems less dramatical

 

[GlowBugTDI]

Theres no fuel pump on an alh. Fuel is pulled from the tank by the injection pump. Its a sealed system.
Where are you applying vacuum in the circuit?

 

[Mongler98]

Not sure but I think there's a check valve inside the hpfp, thats why when I bleed from the pump the problem seems less dramatic

ALH does not have a HPFP.. it has an IP. they have NO check valve.
the check valve for the mk3 and mk4 platforms are at the tank externally.
you should always be bleeding from the pump, to draw fuel into the filter from the tank.
the reason you had a "less dramatic problem" was that your check valve is working properly at the tank. nothing to do with anything else.
Alec2003 is having an issue doing it too fast. its not a fast job. it is when you have a good vac pump to prime it. whats actually happening is what Marc said in post #2. take the fuel cap off or just do it slow. the air is replaced in the tank via the return line so if the return line has fluid in it it will go slower.
as long as you primed the filter thought he pump it means nothing to draw a bit back into the tank but its an indication that there is an issue with the valve

 

[Alec2003]

Thank you very much I will look at the check valve then!

 

[Alec2003]

Theres no fuel pump on an alh. Fuel is pulled from the tank by the injection pump. Its a sealed system.
Where are you applying vacuum in the circuit?

Hard to describe but it's where all the videos shows it, I'm pretty confident that my check valve need to be tested.

 

[Alec2003]

My fuel cap was already removed but it changed nothing, but I know that it is a huge help for priming the fuel

 

[Marc Bourget]

In removing the supply line from the tank outlet, I found an o-ring on the outlet. Never saw that in the Dr. Dan's video, Is there a groove, etc. it should be placed in? Is the check valve in the fuel pick up, or in the coupling to the tank?

There wasn't a brief back flow when I released the vacuum, it was a prolonged gurgling.

That said, the new tank pick up has arrived and I plan to replace the pick up, after drilling the check valve, and repeating the exercise.

All else considered, I successfully vacuumed the fuel line at the pump and ran it without issue. But, the next morning, the tube from the filter to the IP had a large bubble and it repeated the crank without start episode. All the hose fittings appeared tight. Is there someplace else I should be checking for leak(s) that would show up, overnight, between IJ and fuel filter?

Thanks, lots, for your views and advice!

mjb

 

[GlowBugTDI]

Hard to describe but it's where all the videos shows it, I'm pretty confident that my check valve need to be tested.

No hpfp as mongler also stated. So your pulling vacuum pre or post IP (injection pump)?
Whats happening with the car that your doing this? Whats its problem?

 

[GlowBugTDI]

In removing the supply line from the tank outlet, I found an o-ring on the outlet. Never saw that in the Dr. Dan's video, Is there a groove, etc. it should be placed in? Is the check valve in the fuel pick up, or in the coupling to the tank?

There wasn't a brief back flow when I released the vacuum, it was a prolonged gurgling.

That said, the new tank pick up has arrived and I plan to replace the pick up, after drilling the check valve, and repeating the exercise.

All else considered, I successfully vacuumed the fuel line at the pump and ran it without issue. But, the next morning, the tube from the filter to the IP had a large bubble and it repeated the crank without start episode. All the hose fittings appeared tight. Is there someplace else I should be checking for leak(s) that would show up, overnight, between IJ and fuel filter?

Thanks, lots, for your views and advice!

mjb

You most likely have a crack somewhere allowing air in, but no fuel out i guess.

at any point along the lines with the car running can you see bubbles coming unto the line or anything? Make sure fuel filter is properly attached, and the hoses aren't cracked if you just replaced it.

A background story might help if theres anything that changed that caused your issue.

 

[Marc Bourget]

Original problem started with bad fuel. Had the tank pumped out fresh fuel. Ran but, on starting, I'd get a lopey or bouncing idle for the fist 2 min or 1/4 mile. I was putting up with it. Parked it while away for the weekend and when I returned, no start and fuel line from filter to IP had large bubble.

Ordered new fuel pick up, so after receipt, I removed the original only to find out that the mechanic (who serviced the tank to remove the contaminated fuel that started all my problems), forgot to "snap" the top of the pick up to the pick up body before reinstalling the pick up. Thinking that might be the problem, I snapped original back together, reassembled and vacuumed a clear stream from the hose feeding the injector pump. No back flow/siphoning at this time.

Car fired right up and ran well, took a 5-6 mile test drive. All remained well, (I thought) and I parked it until next morning. Going to work this AM, repeat of the crank - no start. Popped the hood and saw lots of bubbles in the clear portion of the supply tube from filter to pump.

Disconnected the far side (return line) of the pump, applied a vacuum, pulled to clear stream of fuel, removed the vacuum source - and immediately got back flow gurgle (8-10 seconds) - fuel siphoning back to tank. Put my finger over the outlet and backflow bubbles continued ???? I never took the cover off the pump. I'm unsure what's happening with the fuel wanting to backflow.

Repeated vacuuming fuel lines from line from tank into filter - back flow; line from filter to pump - back flow; removed banjo fitting on discharge side of pump - back flow. Put finger over IJ outlet and still bubbles ?? That one confuses me.

I'll try allowing the suction to relieve itself before removing the vacuum source but any other thoughts are appreciated.

mjb

 

[Marc Bourget]

Update: Bought a used ALH from a guy in Lancaster, (86,000 miles) No flywheel/clutch. It's on an engine stand at this time.
Purchased a single mass flywheel/clutch combo and would like to change the Timing Belt/water pump, etc., before I install it in my Jetta wagon, but unsure how to find TDC. Can I position the new clutch without a bellhousing mark. For example, can I use the Camshaft lock tool and trust that the position will be adequate for the swap?

 

[AndyBees]

Update: Bought a used ALH from a guy in Lancaster, (86,000 miles) No flywheel/clutch. It's on an engine stand at this time.
Purchased a single mass flywheel/clutch combo and would like to change the Timing Belt/water pump, etc., before I install it in my Jetta wagon, but unsure how to find TDC. Can I position the new clutch without a bellhousing mark. For example, can I use the Camshaft lock tool and trust that the position will be adequate for the swap?

This would have been a good question to post in the 101 or VE/PD categories.

The SMF combo will have a Timing Mark which will likely be on the Pressure Plate in the form of a V. The Flywheel will only bolt on in the correct position.

After you install the flywheel, with the Valve Cover off, rotate the engine over until the Cam Lobes of #1 cylinder are at roughly 10 and 2 O'clock. Then observe the Cam Slot for the lock plate......... it should be in Time. Then, insert the lock plate on the Cam and the Pin in the IP Cog.

Easy work from there with the engine on a stand.

 

[Zak99b5]

I wouldn't.

Remove the glow plug from #1 cylinder and stick a slim wooden dowel in the hole. Turn the motor until you've found the high point of the dowel. Turn the crank clockwise and stop when you see the dowel start to drop. Make a mark on the dowel even with the top of the glow plug hole. Also, make matching marks on the flywheel and block. Then turn the motor counter-clockwise and watch the dowel rise back up and then start to drop, stopping when the mark on the dowel is again even with the top of the glow plug hole. Mark the flywheel again even with the mark on the block you just made. TDC is in the middle between those marks.

 

[dieseldonato]

You can use either method to find TDC. It's very easy on these engines with so many places to shove pins and bars.

 

[Marc Bourget]

Thanks, gentlemen!

What else would you recommend on this engine while on the stand before installation. For example, de-carbon the intake, change crankshaft seal (because flywheel off for extended period,) etc.?
Any special tips, like marking other items in prep of future maintenance that may occur?

 

[AndyBees]

The flywheel being off has nothing to do with the condition of the rear main seal. But, if the engine has over 200k miles on it and the seal looks as if it has been or is leaking, it is a no brainer. ......... you are there, change it with a quality product. It will be settled by the engine is installed. The rear main seal in my formally owned 2000 (son owns it) nearing 390k miles.. does not leak. My 03 is pushing 350k... does not leak. The 02 ALH in my 84 Vanagon is just shy of 210k miles ... does not leak. A friend's 01 Jetta is pushing 450k miles, the rear main seal has been weeping for over 100k miles.

Cleaning the Intake Runners in the Head is as important, if not more important, than cleaning the Intake. When you remove the Intake you break the carbon deposit between the Intake Runners and the Intake. The carbon build up in those runners is far more brittle than in the Intake. Leaving the carbon in the Intake is a big gamble. That stuff can flake off and result in a catastrophic incident ... piston to head, under valves, into the turbo blades, etc. (there are photos in my albums of head disasters like I've described)

If the front main seal is showing signs of leaking, you probably should replace it.

The Cam seal has never been changed in any of the above mentioned vehicles. I have a pile of Cam seals left over from TB kits because if they were not leaking I left them alone. In fact, I have never found an ALH engine with a leaking Cam seal.

Be sure to change the Vacuum Pump seal ....... those things do leak. Put RTV or similar in the "corners" of the Valve Cover gasket.

 

[jayb79]

The only cam seal leak I have ever had is after I changed one.

 

[Marc Bourget]

Cleaning intake runner procedure.

This approach acceptable?

Since the valve cover will be removed to "find" TDC , , ,

Rotate the engine on the stand until the cylinder head is low before removing intake manifold,

Then, rotate the engine until the particular valve is closed, cover the other three intake ports and clean the open port(s) repeating valve closure in turn?

Really appreciate the assistance!

mjb

 

[AndyBees]

Yeah, observing the Cam Lobe for the individual port you are going to clean is the key.

I cleaned the Intake Ports in the 2.0 Gasser engine in my 2011 Tiguan April, 2022.

After setting the Camshaft lobes so that the valves were closed (two Intake Valves per cylinder), I sprayed the entire area with WD-40 and let it soak in for at least an hour. Then I scraped and scraped with an aluminum device I made years ago as well as the use of picks. Then, using vacuum, I sucked out all the crud. Then, I sprayed in a diesel fuel-gasoline-kerosene mix until the port was almost full. I let it soak for at least an hour. Then, I did the scrap and pic, basically feeling in the dark no doubt. Then, I vacuumed all that crud out. Next, with a batch of the same diesel/gasoline/kerosene mix, I began brushing with a human tooth brush.......... over and over, reaching behind the valve stems, etc. Then, after vacuuming out that mess, I sprayed everything down with brake cleaner and vacuumed it out. Then, I used Dawn liquid and water with a new tooth brush........ repeated the scrubbing/brushing two tor three times. Then, after vacuuming out the soapy water mix, I lightly blew out the ports with compressed air and then did a final with brake cleaner and compressed air............. Heck yes, a lot of work, but they were clean when I finished. I've put almost 12k miles on it since then... no issues.

Below are the before and after pics of the same set of ports...

 

[Marc Bourget]

Didn't try a rotary wire brush like a bottle brush?

 

[AndyBees]

Didn't try a rotary wire brush like a bottle brush?

No I did not ......... mainly because I could not find one at any of the local stores in my neck of the woods.
I tried the trick of placing a bunch of Zip Ties in a drill .......... made a mess!

 

[Marc Bourget]

Well, you shoulda removed the Kero/Diesel/Gas solution first! (hahahahaha!)

Any other hints before I throw it into the car?

Thanks, btw!

 

[AndyBees]

Now is a good time to inspect the CV Joints ....... repack the inside joints with grease. The inside ones typically bite the dust first.
And, those sway bar bushings are much easier to access now.

 

[Marc Bourget]

Wilco! I already bought all the suspension pieces, struts, spindles, brakes, lower A arms, bushings, etc.

thanks