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Engine Specific Info and Questions => IDI Engine => Topic started by: deathhare on January 22, 2010, 12:38:13 pm

Title: Air Bubbles!!!??
Post by: deathhare on January 22, 2010, 12:38:13 pm
Some of you may have been watching my build thread on the tex and some of the issues Ive been having since the first start up.
The back story on my problem is that when I got the swap running it was sucking in huge amounts of air.

I got all new OEM lines and new copper washers today. I think the bubbles may be reduced but its still sucking in air.  :(

One good thing today is that I checked the in-tank filter and it was completely clogged with ***.
Cleaned it and now the car literally has about 3x more power.  :D  :thumbup:
It still stumbles at high rpms as the bubbles get real bad I assume? I cant tell if that is what's really happening or not.
I can hand rev it and see bubbles flow thru the clear line so I assume that at high rpm this is what is making the car stumble?

Not sure what to do at this point but its annoying as hell. Any ideas?
The ONLY line that isnt OEM and new in the system is the little line that comes off the tank and to the hardlines.
I guess its my next step really but hoping someone would have some other input.

New pics:

 (http://i75.photobucket.com/albums/i292/deathhare/DSC_0022.jpg)  (http://i75.photobucket.com/albums/i292/deathhare/DSC_0027.jpg)
Title: Re: Air Bubbles!!!??
Post by: Rabbit on Roids on January 22, 2010, 12:56:47 pm
dude, get a cover on your timing belt. like yesterday or sooner..

dont wanna have a rock come up from the road and put a hole in your belt and whammy all your valves.
Title: Re: Air Bubbles!!!??
Post by: deathhare on January 22, 2010, 01:12:50 pm
dude, get a cover on your timing belt. like yesterday or sooner..

dont wanna have a rock come up from the road and put a hole in your belt and whammy all your valves.

I dont have a cover.
SOMEONE on here is donating me one soon though but I havent gotten it yet.  :-X

Not too worried about the lack of it now as I'm not driving the car and DID drive it for 7 years before this without one.
That being said, since I do care a lot about THIS motor, I want one and will have one on it when I start taking it more than a couple miles from home.
Title: Re: Air Bubbles!!!??
Post by: Rabbit on Roids on January 22, 2010, 01:55:23 pm
for a car/engine that nice, its not worth taking the chance in my opinion.
Title: Re: Air Bubbles!!!??
Post by: GEE-BEE on January 22, 2010, 04:46:36 pm
I would plug the rear lines and do A vacuum test, then do the front lines..

You will find it

GB

Title: Re: Air Bubbles!!!??
Post by: RabbitJockey on January 22, 2010, 05:22:08 pm
yes, perhaps pressurize them with air and spray all the unions with windex.  windex is a great leak detector.  i have learned this through my profession
Title: Re: Air Bubbles!!!??
Post by: deathhare on January 22, 2010, 06:22:26 pm
It seems like pressurizing them would just make a leak anyway eventually.
I like the idea of a vacuum test better but I cant see how you'd know where it was leaking in that way though.  ???
Title: Re: Air Bubbles!!!??
Post by: 8v-of-fury on January 22, 2010, 07:12:34 pm
It seems like pressurizing them would just make a leak anyway eventually.
I like the idea of a vacuum test better but I cant see how you'd know where it was leaking in that way though.  ???

well how much vacuum does an injector pump pull? pressurizing it with the same or a little more pressure would probably find your leak. Wherever it is that is leaking... is being subjected to a certain amount of suction to draw air in, and this may solve it.

You have replaced all the lines but the one little piece? lool talk about quality ;) jk

Car is tits man :)
Title: Re: Air Bubbles!!!??
Post by: fatmobile on January 22, 2010, 11:13:11 pm
Air bubbles don't often mean you have an air leak in your fuel lines.
 It usually means you are pulling a vacuum.
 A little story for ya:
 I once had air bubbles in my fuel line,
 looked like they were coming from the filter, since I had clear lines before and after the filter and no visible bubbles were entering the filter.
 
 My plan:
 start the car and slowly lower the filter into a bucket of diesel,
 when the bubbles stop; that's where the leak is pulling fuel in, get it?
 I slowly dipped the fuel filter until it was totally covered in fuel,..
 and bubbles were still coming from the filter.

 I had a normal banjo bolt in the pump output,
 it had no restrictor.
 The pump was pumping full blast,
 pulling so much so fast; it created a vacuum that pulled the air out of suspension.

 A vacuum gauge on the fuel line will tell you if the tank vent is clogged,.. before it collapses your tank.
 It will tell if your fuel is gelling way before you are sitting beside the road in a non-running car in the brutal cold.
 It will tell if the in-tank screen is clogged.
 It will tell if there is a little chunk in the line right before the filter, that can't quite make it through the barb,.. so it sits in the way partially blocking fuel flow.
 
 I wanted to know how hard the pump was working to pull vegetable oil at first,
 I now concider a vacuum gauge on the fuel line to be manditory, all my diesel VWs have them.
 Most of us will find ourselves broke down beside the road before we concider it to be an important gauge.

 They almost always read 0.
 If it gets to 5 I get concerned,
 if it gets to 7 I do something about it.
 So get a gauge with the numbers far apart between 0 and 10, something with a large sweep.
 Ebay has the best prices.
Title: Re: Air Bubbles!!!??
Post by: Quantum TD on January 23, 2010, 12:32:24 am

 I had a normal banjo bolt in the pump output,
 it had no restrictor.
 The pump was pumping full blast,
 pulling so much so fast; it created a vacuum that pulled the air out of suspension.

I didn't think of that Shannon. The bolt for the return should say OUT of the top of it. Check the insides to see if the restrictor is in there. Also, blow air back thru both feed and return line. And, blow through the vent tube (sticks into the fender). If your gravity valve is bad, it could cause a vacuum issue. Obviously, if you hear a "swoosh" when you remove the fuel cap, you've got something wrong (clogged vent tube or faulty gravity vavle).


Having said that, I think if you replace all the feed and return hoses and clean out that in-tank screen, you should be good to go. I doubt it's an issue with the hard lines.
Title: Re: Air Bubbles!!!??
Post by: deathhare on January 23, 2010, 06:59:29 am
The bolt doesnt say OUT on it but I just looked and found one in my toolbox that does.
Wonder where that came from.  ;D

It clearly has a restrictor in it.
I'm hoping this will help me out although I dont really understand what it does for things. Obviously it restricts the flow back into the tank but what does that do for the whole system?

Next weekend I am planning to put a new tank in the car since when I pulled that in-tank screen I saw that the tank was filled with trash and even some rust in there. I dont feel like cleaning this one since a new baffled tank is $134 shipped.
Just ordered a the tank, new filters and tank outlet hose.
At that point I'll blow through the lines to be sure they're all clear and install this OUT bolt.

That should have me fixed up or what?  ???


Title: Re: Air Bubbles!!!??
Post by: GEE-BEE on January 23, 2010, 07:51:16 am
Check you tank strap seals, you dont want metal to metal on those ..

If you need some let me know?

P.S. probly time for a new cap also

GB
Title: Re: Air Bubbles!!!??
Post by: deathhare on January 23, 2010, 07:57:22 am
It was the bolt!!
Car hauls ass, no stumbling and black smokes at WOT for the first time.  ;D


Thanks to everyone for your help and fatmobile for mentioning that.  8)
Title: Re: Air Bubbles!!!??
Post by: Rabbit on Roids on January 23, 2010, 08:01:15 am
it just had a normal un restricted IN bolt on the OUT side of the pump? that musta ran like crap. no timing advance cant be good.
Title: Re: Air Bubbles!!!??
Post by: deathhare on January 23, 2010, 08:03:26 am
Yep. ;D
Title: Re: Air Bubbles!!!??
Post by: 91redjetta on January 23, 2010, 08:39:13 am
your car is beautiful by the way..
Title: Re: Air Bubbles!!!??
Post by: deathhare on January 23, 2010, 09:39:16 am
Thanks  ;D
Title: Re: Air Bubbles!!!??
Post by: Quantum TD on January 23, 2010, 10:52:26 am

Next weekend I am planning to put a new tank in the car since when I pulled that in-tank screen I saw that the tank was filled with trash and even some rust in there. I dont feel like cleaning this one since a new baffled tank is $134 shipped.
Just ordered a the tank, new filters and tank outlet hose.


Just make sure the tank has baffles and the collection bowl on the bottom. I've seen some aftermarket tanks which lack one or the other. You don't want to have fuel cut-out around corners. If the tank lacks one or the other, lining your existing tank is an option. Tennessee Diesel in Columbia can do it for about $150. Not any cheaper, but at least you know you won't fuel starve.

Good to hear on the bubble issue. Can't wait to see the car in person.
Title: Re: Air Bubbles!!!??
Post by: RabbitJockey on January 23, 2010, 02:57:04 pm
just so u understand what the out bolt does better, it restricts the return line to the tank in order to build internal pressure for the pump. the more rpms you have the more the internal pressure  pushes the timing advance piston and advances the timing for better high rpm performance.  so like somebody else said, you were running the car with out the timing advance so it ran like *** obviously.
Title: Re: Air Bubbles!!!??
Post by: deathhare on January 23, 2010, 03:59:30 pm
Thanks for the info on the bolt. Makes sense. Lesson learned too. :)

According to many people who have bought this tank, it will have the internal bowl/baffles... so I should be set.
The Spectrum made tank part#VW4B is the only one they make that has it inside (so I've heard from people who have bought both)... the VW4C does not and therefore sucks.  8)
Title: Re: Air Bubbles!!!??
Post by: jack's lack on January 24, 2010, 09:25:44 am
a bit off topic, but would you post a link to your build thread on the tex? I searched, but everyone knows the tex search fails.
your car looks super nice. I'm glad you fixed your problem. This forum is awesome.

oh btw, I just found your thread. Nice build super clean. I realized whatever I do with my transmission I need to paint it yours looks the stuff.
Title: Re: Air Bubbles!!!??
Post by: fatmobile on January 24, 2010, 11:31:44 am
Took me awhile to figure out why they used a banjo bolt with no hole in it,.. there is a hole but it was so small I didn't see it.
 Well, that was an easy fix, ha.
Title: Re: Air Bubbles!!!??
Post by: deathhare on January 24, 2010, 08:06:07 pm
Yeah thanks a lot fatmobile.  :)

Link to my build thread. http://forums.vwvortex.com/zerothread?id=4579598 (http://forums.vwvortex.com/zerothread?id=4579598)
Not enough pics in it. I'm more of a worker than a pic shooter when doing car stuff.... even though I teach photography for a living.  ;D