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Roy Hendriks
Samba Member
Joined: July 27, 2019
Posts: 6
Location: Netherlands
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 Posted: Sat Jul 27, 2019 2:49 am Post subject: Unusual airhose connection? |
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Hi there, I own a 411 LE Variant from 1972 with a 1.7 D-jetronic injection.
Sadly Haynes doesn't have an answer to the next dilemma.
My breatherbox has two connections that seem original. Unfortunately the top one was not connected and I can't seem to figure out where connection number 2 should go? With running engine it is sucking in air. Number 1 goes to the inlet air distributor.
Since my engine does not run properly, I need al air connections to be connected in the right way. I can't find foto's or literature of a similar model anywhere.
I also seem to have a distributor with only 1 vacuum outlet, a bit strange as most others have 2 ??
Can anyone help, preferably with pictures! Thanks
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MarcVoss
Samba Member
Joined: July 21, 2019
Posts: 67
Location: DE, Munich
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| Posted: Sat Jul 27, 2019 6:55 am Post subject: Re: Unusual airhose connection? |
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Hi Roy,
is connector #2 still open, or has it been closed?
Your car has automatic transmission?
The way from the crankcase should be between filter and throttle, my opinion.
It looks like something selfmade.
_________________
Best Regards from Germany, the origin country of Volkswagen.
Marc |
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raygreenwood
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Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Sat Jul 27, 2019 8:14 am Post subject: Re: Unusual airhose connection? |
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Actually with D-jet injection the red 12mm hose from the oil chimney (PCV valve) and the engine is always to the center manifold....not between the air filter and throttle valve. That would be for 1974 L-jet injection only.
The part with two nipples on it IS an actual VW part....but it is in the wrong place....depending on which engine number, which center manifold number and air cleaner assembly you have.
The part number of that rubber part is 022 129 637 B...listed as "branch piece for air intake distributor".
BUT...it connects to the center intake plenum....and not to the oil breather box like it is one your engine.
Depending on which engine and air cleaner it can connect like this:
See it in the red circle?....it connects manifold vacuum to the 12mm hose for the oil breather and a small bore hose with manifold vacuum to the air cleaner warm air flap dashpot. Its is listed as part "set #25" which is the short hose and long hose to the air cleaner for vacuum supply
The other way this dual connector is used:
Still attached to the center manifold and the 12mm hose again, goes to the oil breather chimney to supply manifold vacuum to the PCV valve....but the smaller hose branches to the manifold pressure sensor (MPS) to supply vacuum to it.
There are several versions of the center manifold. One of the tuning issues with D-jet on the type 4 engines is that the MPS really has a few issues with being connected on the same connector as the 12mm PCV hose...because the PCV valve opens without any reference to teh ECU at low RPM or throttle transition points...it can supply an untimed vacuum variance to the MPS
This is why a handful of us found better performance and tuning with this connection set up...by taking the insides out of teh PCV valve...and inserting a fixed 2-3mm orifice in the 12mm line to flow constant PCV. We just slightly retune the MPS to compensate.
Ray |
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Roy Hendriks
Samba Member
Joined: July 27, 2019
Posts: 6
Location: Netherlands
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| Posted: Sat Jul 27, 2019 8:15 am Post subject: Re: Unusual airhose connection? |
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Hi Marc,
I can confirm both. It is an automatic and yes it was open and with running engine it´s is sucking in air. |
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MarcVoss
Samba Member
Joined: July 21, 2019
Posts: 67
Location: DE, Munich
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| Posted: Sat Jul 27, 2019 8:53 am Post subject: Re: Unusual airhose connection? |
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This is my engine, it‘s a 1971 model and manual gearbox, so a little bit different, but maybe it helps, the hoses are all correctly connected.
Your part is later used by me to fix the broken one (see in the upper right position near the filter), but one hole is closed now.
_________________
Best Regards from Germany, the origin country of Volkswagen.
Marc
Last edited by MarcVoss on Sat Jul 27, 2019 10:19 am; edited 1 time in total |
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Roy Hendriks
Samba Member
Joined: July 27, 2019
Posts: 6
Location: Netherlands
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| Posted: Sat Jul 27, 2019 9:01 am Post subject: Re: Unusual airhose connection? |
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Ray,
Thank you very much for your elaborate reply.
First impression is that you might about mixing up the 2 rubbers I saw that there are 2 exits on the intake air distributor. So both yellow lines are there and connected properly.
Took the branch piece off butt can't seem to find a number on it. Then I noticed that i don't have connectionline 25 from the first picture! So I will be changing the connections tomorrow and see if it's a gamechanger and hopefully the engine won't stall anymore or run as rich as it does.
Only question left is about my distributor, it has only one vacuumoutlet which goes to the Throlttle house back connection (50). 60 is connected to the intake air distributor, can't see that on the pictures. |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Sat Jul 27, 2019 9:32 am Post subject: Re: Unusual airhose connection? |
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| Roy Hendriks wrote: |
Hi Marc,
I can confirm both. It is an automatic and yes it was open and with running engine it´s is sucking in air. |
Ok...no air leaks allowed at all with D-jet.
So...for the moment you could get rid of the problem just by plugging that small 3-4mm nipple on top...and everything else looks correct.
Here is your picture of your engine:
Note that the two hoses marked in yellow...are 100% correctly placed and connected. In fact if you look at the end where they connect to the center manifold you will find a double nipple connector just like you have on top of the oil breather chimney.
As I noted...its not a non- VW part...its just in the wrong place. SA normal 90* elbow with a 11-12mm opening fits on top of the breather.
Ray |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Sat Jul 27, 2019 9:52 am Post subject: Re: Unusual airhose connection? |
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| MarcVoss wrote: |
This is my engine, it‘s a 1971 model and manual gearbox, so a little bit different, but maybe it helps, the hoses are all correctly connected.
Your part is later used by me to fix the broken one (see in the upper right position near the filter), but one hole is closed now.
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Your hose are connected properly for a European model ONLY.
USA/North American models like his...and my manual transmission 412...ALL have a spring loaded PCV valve in the oil breather box. That PCV valve runs on full manifold vacuum...and ALWAYS goes to the center manifold and not to the boot/hose between air cleaner and throttle valve.
Here is the PCV valve knurled nylon mounting nut on his engine shown by the yellow arrow
Here is the North America vacuum routing diagram showing the correct 12mm hose routing from the PCV valve on the oil chimney to the left back corner of the intake manifold. The hose in question is marked in yellow.
Note that there are no hoses in this diagram that go to the boot between the air cleaner and TB.
Also note....that the small bore red supply hose coming from teh air cleaner...also shows that it goes to the center manifold at this point. Depending on teh equipment of the particular car...the air cleaner vacuum motor for warm air can go to several places.
His appears just to loop to both sides of the valve on the air cleaner so it is in fact improperly connected. I will have to see where his model actually connects to......but the 12mm hose from the oil breather on his engine is connected properly to the center manifold.
Ray |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Sat Jul 27, 2019 1:41 pm Post subject: Re: Unusual airhose connection? |
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| Roy Hendriks wrote: |
Ray,
Thank you very much for your elaborate reply.
First impression is that you might about mixing up the 2 rubbers I saw that there are 2 exits on the intake air distributor. So both yellow lines are there and connected properly.
Took the branch piece off butt can't seem to find a number on it. Then I noticed that i don't have connectionline 25 from the first picture! So I will be changing the connections tomorrow and see if it's a gamechanger and hopefully the engine won't stall anymore or run as rich as it does.
Only question left is about my distributor, it has only one vacuumoutlet which goes to the Throlttle house back connection (50). 60 is connected to the intake air distributor, can't see that on the pictures. |
Closing off the small open connector on top of the oil breather box area WILL be the game changer.
See....D-jet is manifold pressure controlled. Any vacuum leak downstream of the throttle plate...is read by the manifold pressur sensor...as an open throttle movement. So with that small nipple open...your MPS is running the engine VERY rich...so yes..it will stall a lot and run poorly until you get it up in the mid range rpm and even then it may run poorly and be hard to accelerate.
The little vacuum dashpot on the air cleaner is mainly for starting in cold weather. It should shift inlet air to a warm air duct so you will not see any better running from that repair...but it should warm up a little better in cold weather.
So...from the picture you have a single vacuum advance only unit on your distributor.
It should go to a small 3mm line that fits onto a 2.5mm vertical brass inlet nipple on teh backside of the throttle housing just about 1/8" forward of the idle adjusting screw.
You can see this very clearly in the picture of MarcVoss's very well organized engine compartment.
BUT....your engine HAS the small hose from this correct spot on the throttle body housing....going to a spot CLOSE to your vacuum advance unit....but is not going to the correct vacuum nipple.
The vacuum nipple on your advance can....is going all the way to the right...looping back to the left...and going under the front side of the TB. That is the wrong place. Where yours appears to be going to...is the VACUUM RETARD hose connection.
This would mean that you would have vacuum advance on full time when idling with the throttle closed...but lose advance as soon as you open the throttle...another recipe for stalling and poor performance.
So...connect the vacuum advance up properly...remove the small hose to the nipple on the underside of the throttle body and cap that connection with a rubber cap.
You will also probably have to reset the ignition timing correctly.
Also remove the distributor cap and with a flashlight look for a 3-4 digit number stamped on teh advance unit arm and tell us what it is.
Ray |
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Lars S
Samba Member
Joined: October 04, 2007
Posts: 786
Location: Sweden
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| Posted: Sun Jul 28, 2019 5:56 am Post subject: Re: Unusual airhose connection? |
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| raygreenwood wrote: |
Your hose are connected properly for a European model ONLY.
USA/North American models like his...and my manual transmission 412...ALL have a spring loaded PCV valve in the oil breather box. That PCV valve runs on full manifold vacuum...and ALWAYS goes to the center manifold and not to the boot/hose between air cleaner and throttle valve.
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You are right Ray, the early D-jet cars (-70 and possibly part of -71) had no PCV-valve but a straight hose from the crankcase vent box to the air cleaner, just like on MarcVross photo. Dont know i this was a specific European thing though.
From what I believe the PCV valve was introduced at the same time that vented valve covers were introduced.
/Lars S
_________________
Porsche 914 -72, Bahia Red daily driver 
VW411 2-d -70, White, sold 
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold |
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Sun Jul 28, 2019 7:57 am Post subject: Re: Unusual airhose connection? |
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| Lars S wrote: |
| raygreenwood wrote: |
Your hose are connected properly for a European model ONLY.
USA/North American models like his...and my manual transmission 412...ALL have a spring loaded PCV valve in the oil breather box. That PCV valve runs on full manifold vacuum...and ALWAYS goes to the center manifold and not to the boot/hose between air cleaner and throttle valve.
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You are right Ray, the early D-jet cars (-70 and possibly part of -71) had no PCV-valve but a straight hose from the crankcase vent box to the air cleaner, just like on MarcVross photo. Dont know i this was a specific European thing though.
From what I believe the PCV valve was introduced at the same time that vented valve covers were introduced.
/Lars S |
Lars....that is correct!.....because....the valve covers are not actually "vented" 
The 12mm steel tubes in the rocker box cast in bosses are INLETS. They are the main part of the PCV system.
The air cleaners used with the PCV system whether oil bath or the later round paper filter element used by the last of the D-jet 412's here in North America......had a specific/extra connector nipple. This nipple supplied already filtered air.
The 12mm hose connected to it went to a 3 way splitter/flame trap (another PCV system only part)....screwed to the cooling shroud right by the cooling flap control cable. From here it split to a 12mm hose for each valve cover/rocker box.
The PCV valve and full manifold vacuum connection is in the top of the oil chimney.
That PCV valve and vacuum connection.....PULL ....freah air from the air cleaner, through the splitter, into each rocker box, through the pushrod tubes into the engine.....and finally out the top of the case and through the oil baffel/PCV valve and into the center manifold.
Ray |
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Roy Hendriks
Samba Member
Joined: July 27, 2019
Posts: 6
Location: Netherlands
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| Posted: Mon Jul 29, 2019 12:21 pm Post subject: Re: Unusual airhose connection? |
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Well, get the feeling i'm slowly getting there.
I switched my branche piece with the 90-angle in the back so i could connect line 25 to the small nipple on the airfilter as well.
Final questions/answers.
1-I have a spring loaded PCV valve, but it's a european model, do you agree that that is correct?
2-I can't figure out where the red loop line should go? I now have 2 connections at the bottom of the aircleaner. How about those?
3-The number on the vacuum arm is: 407 (realy curious what that means) and reminds me to clean/check the triggering contacts from the distributor.
4- Ray, on your 3th picture there is a hose (60) going from the front of the throttle valve housing to the vacuum pot on the distributor 'back entrance'. Mine is going to the right side of the air distributor. No clue if that is correct. On Marc's engine it seems to be none existing.
Here's the latest actual foto of the setup, hope everything is visible.
Again thanks a lot for the great help so far!
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raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21520
Location: Oklahoma City
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| Posted: Mon Jul 29, 2019 1:58 pm Post subject: Re: Unusual airhose connection? |
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| Roy Hendriks wrote: |
Well, get the feeling i'm slowly getting there.
I switched my branche piece with the 90-angle in the back so i could connect line 25 to the small nipple on the airfilter as well.
Final questions/answers.
1-I have a spring loaded PCV valve, but it's a european model, do you agree that that is correct?
2-I can't figure out where the red loop line should go? I now have 2 connections at the bottom of the aircleaner. How about those?
3-The number on the vacuum arm is: 407 (realy curious what that means) and reminds me to clean/check the triggering contacts from the distributor.
4- Ray, on your 3th picture there is a hose (60) going from the front of the throttle valve housing to the vacuum pot on the distributor 'back entrance'. Mine is going to the right side of the air distributor. No clue if that is correct. On Marc's engine it seems to be none existing.
Here's the latest actual foto of the setup, hope everything is visible.
Again thanks a lot for the great help so far!
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Ok.....first....why would you thibk your car is a European model? Everything I see.....PCV hoses....PCV valve....automatic transmission....throttle dashpot etc.....says USA spec model.
Nice color coded hose diagram!
Blue hose correct
Orange hose -correct
Green hose -correct
Purple hose -correct
The dark red hose to the throttle dashpot-correct
The lighter red hose coming from the right side of the manifold....is either 100% c9rrect or partially correct. It does connect from the manifold to that spot on the throttle body housing....but it should have a "Y" in it....probably right behind the throttle dashpot....where it connects to the modulatot valve on the Automatic transmission.
As for the small hose connections to the air cleaner.....let me check on this. It has been years since I used the oil bath aid cleaner with that vacuum changeover valve. My car is running the late D-jet plastic filter with paper elment that does not have those hoses. I need to look in my emissions hose chart in my book. Ray |
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Roy Hendriks
Samba Member
Joined: July 27, 2019
Posts: 6
Location: Netherlands
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| Posted: Tue Jul 30, 2019 12:36 pm Post subject: Re: Unusual airhose connection? |
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Check, you were right About the y-section behind the throttle dashpot and it’s going right to the backwall so probabily to the automatic modulator Valve indeed and to the throttle house so that must be correct.
Thank you for sorting that out. Will focus in ignition next because the result is nog there yet. Can’t immagine those 2 small hoses beneath the filter Will make a difference.
I couldn’t imagine i have a us spec car because i bought the car in Belgium who bought iT from a German garage who used iT as a company car. That historische Goes back about 20 years(hense the questionable greenisch respray) Plus the speedo is in Km/h. Butt what do ik Know about 411s so far, i’ll take your word for granted 
Cheers |
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Roy Hendriks
Samba Member
Joined: July 27, 2019
Posts: 6
Location: Netherlands
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| Posted: Tue Jul 30, 2019 12:44 pm Post subject: Re: Unusual airhose connection? |
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Found it! My first connection wasn't that bad😜
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Rauno Koskinen jn hv
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Joined: August 14, 2019
Posts: 1
Location: Finland
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| Posted: Wed Aug 14, 2019 4:50 am Post subject: Re: Unusual airhose connection? |
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Hello!
Just adding few photos of my -72 1,7. D-Jet engine (european), should be all original.
Maybe the hose in question was attached wrong way round. Connection with two holes is attached to the plenum and thin red hose goes from there to the aircleaner.
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