| Author |
Message |
bugbenginer
Samba Member
Joined: December 26, 2012
Posts: 147
Location: boise, id
|
 Posted: Thu Feb 23, 2017 9:45 am Post subject: No power |
 |
|
Hi there,
I just bought a 73' 412 and I just changed the oil, plugs, wires, rear brake pad, and wheel cylinders (all done by a VW mechanic, because I didn't have much time). I don't seem to be getting full power, meaning, I can drive the car down a flat road and when the automatic transmission is shifting it shifts a little hard but wont go passed 2nd gear, if a hit a downward hill I can go through all 4 gears no problem and really smooth shifting but once I hit an upward hill or flat road its back to 2nd gear and lack of power?
My mechanic says transmission shift solenoid automatic vacuum modulator valve?
any help? |
|
| Back to top |
|
 |
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
|
| Posted: Thu Feb 23, 2017 10:36 am Post subject: Re: No power |
|
|
I cant get into all of this right now.....but look at Mr. Whites thread as well.
Lack of power is NOT a transmission issue. It is an engine issue. Does this engine still have the original injection or carburetors?
The rough shifting is caused by poor or incorrect fluid pressure. Fluid pressure is affevted by poor engine output.....because the engine torque affects torque converter lock up....and...poor engine running affects the vacuum signature ....which governs the main fluid pressure through the vacuum moduoator valve on the transmission.
If the engine is injected.....you MUST make sure that there ard "0" vacuum leaks....anywhere. the vacuum leaks are bypassed air that do not get fuel dosage from the metering unit. Vacuum leaks also affect fuel prezsure as you have a vacuum variable fuel pressure regulator.
Vacuum leaks wise....you need to address:
Throttle body o-ring to center manifold
Throttle shaft seal
Intake runner boots
Intake to head manifold gaskets
Injector tip seals
PCV hoses from cylinder head to oil chimney/air cleaner connection
Oil chimney gasket
PCV valve diaphragm in the oil chimney
Oil chimney connecting hose to air cleaner
Vacuuum advance unit hoses
Fuel pressure regulator vacuum hose to TB
Auxiliary air regulator function and hoses to center manifold
Connecting boot between MAF and throttle body MUST be clamped and must be free of ANY cracks.
EGR valve if you have one
There are "0" vacuum leaks allowed in this system.
Fuel pressure must be checked at idle and at wide open throttle. Check the book but at idle the fuel pressure should be somewhere around 32 psi....rising to somewhere around 42 psi when the throttle is open.
Ray |
|
| Back to top |
|
|
bugbenginer
Samba Member
Joined: December 26, 2012
Posts: 147
Location: boise, id
|
| Posted: Thu Feb 23, 2017 2:06 pm Post subject: Re: No power |
|
|
| yes, the engine still has the original injector. |
|
| Back to top |
|
|
mr white
Samba Member
Joined: October 02, 2005
Posts: 1193
Location: beautiful Oregon & Mohave County, AZ
|
| Posted: Thu Feb 23, 2017 8:33 pm Post subject: Re: No power |
|
|
| Was this the yellow one on CL awhile ago? So your engine revs and seemingly feels like it runs on all four cylinders but your transmission is barely moving? Is this correct? If this is the case your auto trans will have a modulator pressure test port. You will need a oil pressure gauge, I actually have the MAC tool AT pressure gauge set. You will need to find the modulator specs and compare them to what you have. I know on Mercedes diesel Ats you can externally adjust modulator pressure. You also might be able to test governor pressure. I do not have any of those 412 AT manuals as of yet. Maybe a shop in Boise has someone with the knowledge? Most of the guys that were young when the 412 were new are retired or are soon to be. |
|
| Back to top |
|
|
bugbenginer
Samba Member
Joined: December 26, 2012
Posts: 147
Location: boise, id
|
| Posted: Thu Feb 23, 2017 9:18 pm Post subject: Re: No power |
|
|
Yes, this is the yellow one that was on Craigslist, how did you know?
I just hooked up a vacuum hose up to the modulator and sucked on it as hard as I could and it held my tounge with ease so I think that part is good. Maybe that vacuum line going from the modulator to the intakr manifold has a leak?
Thoughts? |
|
| Back to top |
|
|
mr white
Samba Member
Joined: October 02, 2005
Posts: 1193
Location: beautiful Oregon & Mohave County, AZ
|
| Posted: Thu Feb 23, 2017 9:52 pm Post subject: Re: No power |
|
|
| Lucky guess. Nice car. I think a mityvac pump is in order for what you tried. Yes indeed you may have a vac leak some place. Maybe your trans fluid level is low? Maybe the modulator isn't working correctly? Maybe there is a restriction in the trans? Too many maybes. You and I need a trouble shoot man for this. |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
|
| Posted: Thu Feb 23, 2017 10:47 pm Post subject: Re: No power |
|
|
Thjs transmission is actually a type 3 part. It is the 003 automatic.
The brown Bentley manual for type 3 has one of the more generally complete troubleshooting sections for the trans.
You really need to hook up the pressure gauges to the outer ports listed in the manual and do the driving test. Yes....the modulator is externally adjustable with a 4mm allen wrench through the vacuum nipple.
But....long before you start that...all MUST be perfect in the fuel system, engine vacuum system and tuning.
Ray |
|
| Back to top |
|
|
bugbenginer
Samba Member
Joined: December 26, 2012
Posts: 147
Location: boise, id
|
| Posted: Fri Feb 24, 2017 9:19 pm Post subject: Re: No power |
|
|
Ok, I hooked up a vacuum pump to the modulator valve and it held 40 pounds for an hour so I think the modulator valve is Good, then I replaced the entire vacuum line from the modulator valve to the manifold. Took it on a test drive and didn't change anything, it seemed like it wanted to shift better then last time.
Should be testing the modulator cold or with the car running?
Should I just start replacing all sketchy vacuum line or check somewhere else? |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
|
| Posted: Fri Feb 24, 2017 10:07 pm Post subject: Re: No power |
|
|
| bugbenginer wrote: |
Ok, I hooked up a vacuum pump to the modulator valve and it held 40 pounds for an hour so I think the modulator valve is Good, then I replaced the entire vacuum line from the modulator valve to the manifold. Took it on a test drive and didn't change anything, it seemed like it wanted to shift better then last time.
Should be testing the modulator cold or with the car running?
Should I just start replacing all sketchy vacuum line or check somewhere else? |
Listen carefully....STOP MESSING WITH THE TRANSMISSION!
This system....MUST, MUST, MUST, MUST, MUST.......MUST......have the engine parameters spot on before you can even start teating transmission issues.
1. If the engine ia not putting out full power....the transmission will shift poorly
2. If you have even the slightest vacuum leak...anywhere in the engine/fuel injection system....the engine will put out poor power and the transmission will shift poorly.
3. If the fuel pump and regulator system has ANY deficiencies.....that cause low pressure, low volume, or variable pressure not planned by the fuel preszure regulator......the engine will run poorly.....and the transmission will shift poorly.
4. If the electrical system has any issues......low voltage or poor grounds....the engine will run poorly....and the transmission will shift poorly.
The amount of vacuum the modulator valve is irrelevant to whether it works properly or not. Its nice that its not leaking....but that says nothing of what its actually doing....or if it even has the correct vacuum signature coming to it from the engine.
Seriously. Slow down....and do whats required for the engine FIRST. Ray |
|
| Back to top |
|
|
bugbenginer
Samba Member
Joined: December 26, 2012
Posts: 147
Location: boise, id
|
| Posted: Wed Mar 01, 2017 7:07 pm Post subject: Re: No power |
|
|
Ok. Just got my 412 back from a VW mechanic. They did a bunch of work getting proper vacuum and the whole 9 yard do test after test , and they cant figure out why it won't shift into 3rd gear and it's still got to g very hard when when going from park to D and then when hitting second gear. End result , they said they did a their knowledge allowed them to do, so this is the deck d VW mechanic from a shop that couldn't figure this out, out a bunch of money and still the problem is the same , back at square 1.
What now? |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
|
| Posted: Wed Mar 01, 2017 8:44 pm Post subject: Re: No power |
|
|
| bugbenginer wrote: |
Ok. Just got my 412 back from a VW mechanic. They did a bunch of work getting proper vacuum and the whole 9 yard do test after test , and they cant figure out why it won't shift into 3rd gear and it's still got to g very hard when when going from park to D and then when hitting second gear. End result , they said they did a their knowledge allowed them to do, so this is the deck d VW mechanic from a shop that couldn't figure this out, out a bunch of money and still the problem is the same , back at square 1.
What now? |
First....what has been done to the engine to make sure it is running properly. If the engine is not running SPOT ON.....your transmission will never shift right. NEVER!
What do you mean they did "a bunch of work".....what work?.....and where are you measuring vacuum?
Understand.....if your engine is putting out low or incorrect power.....the vacuum is meaningless. The engine first has to provide correct power to the torque converter.
The only things you should be worried about with the transmission...until the engine is fully sorted out.... are these items:
1. Make sure the correct fluid is in the transmission, the filter is clean and its at the correct level.
2. Check the oil in the differential. If on level ground you remove the fill plug on the differential section and oil begins pouring out.....then your automatic section is leaking transmission fluid into the gear oil.
This happens on 100% of these eventually. If you drive on it...it will destroy the ring and pinion.....violently. There is a seal, and o-ring and a paper gasket between the automatic section and differential section that MUST be changed every 7 years or 70k miles.
There was a factory bulletin to this effect for late 70s early 80's audis and VW with largely the same transmission. Once the transmission is out....about a 1.5 hour job getting it out.....it takes about 1 hour or less....very simple.....to change the seals.
3. Once the engine is fully sealed and checked for proper tune....which can only really done with an exhaust sniffer......the very next thing that you should be doing is the driving test with gauges hooked up to the main pressure fluid port on the right side of the transmission.
When you do this test....you can then adjust the vacuum modulator valve on the transmission with a 4mm allen key through the vacuum nipple. With age.....the fluie pump pressure usually puts out a little less pressure...so the shifting is hard.
If the shop you took your car to does not know these things.....they have no business working on this car.
4. You can adjust the bands via the pinch bolts on the outside of the transmission.
The driving test, pressures and the band adjustment are in the automatic transmission section of the Brown Bentley manual for type 3.
To be polite......this is not a bug. It does not respond at all to casual tinkering. You need to do things in order and do them right......or it will destroy parts you cannot replace.....and cost is not the object. They are simply not available.
If you REALLY want help....we can help.....but start at the beginning. What has been done to the engine. Until we know that....the transmission is irrelevant. Ray |
|
| Back to top |
|
|
bugbenginer
Samba Member
Joined: December 26, 2012
Posts: 147
Location: boise, id
|
| Posted: Thu Mar 02, 2017 11:25 am Post subject: Re: No power |
|
|
Ray-
First off, thank you for all the effort you have put toward in helping me this far.
Here is a list of the work that was done as per invoice word for word.
- replaced spark plugs and wires
- replaced vacuum retard hose, smoke tested for additional vacuum leaks, (intake boot leaking at thermoswitch hose nipple
- adjust throttle positioner gap 0.0 ->.022
- Clean & lubricatred distributer. Adjust dwell 41*->46*
-Attempt to check ignition timing but too much bounce to get accurate reading
-check ATF & level
there is is word for word from 2 different shops and neither one can figure out my shifting issue. |
|
| Back to top |
|
|
KTPhil 
Samba Member
Joined: April 06, 2006
Posts: 34002
Location: Conejo Valley, CA
|
| Posted: Thu Mar 02, 2017 11:40 am Post subject: Re: No power |
|
|
| bugbenginer wrote: |
-Attempt to check ignition timing but too much bounce to get accurate reading |
I'd check into this next. |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
|
| Posted: Thu Mar 02, 2017 12:31 pm Post subject: Re: No power |
|
|
| bugbenginer wrote: |
Ray-
First off, thank you for all the effort you have put toward in helping me this far.
Here is a list of the work that was done as per invoice word for word.
- replaced spark plugs and wires
- replaced vacuum retard hose, smoke tested for additional vacuum leaks, (intake boot leaking at thermoswitch hose nipple
- adjust throttle positioner gap 0.0 ->.022
- Clean & lubricatred distributer. Adjust dwell 41*->46*
-Attempt to check ignition timing but too much bounce to get accurate reading
-check ATF & level
there is is word for word from 2 different shops and neither one can figure out my shifting issue. |
Ok....  ...now we are getting somewhere.....OK....this is a 1973 right? With a 1.7 liter engine right?...and not a 1.8L right?
Please read what I am going to take the time to write...carefully. Do not skim. If you need to ask questions to understand..please do so.
For some reason I was thinking you noted it was a 1974 making it an L-jet injected car.
But if its a 1973 it should be D-jet injected. The fact that you noted that it has a throttle positioner pretty much makes it D-jet.
You are likely NOT going to find a general air cooled VW shop that is able to work on this injection. Few could work on it back in the day...virtually none can work on it now.
Bear this in mind.....with D-jet....you are not allowed a SINGLE vacuum leak no matter how slight it is....none....nada. You will not find the vacuum leaks by smoke testing while the car is sitting still. Many of the vacuum leaks that will get you are small and concerned with the manifold....and only open up and leak while the engine is vibrating while underway.
It is a manifold pressure controlled injection system. Even the slightest vacuum leak will cause the manifold pressure sensor to read that vacuum leak as a throttle movement. This will feed fuel by changing injector pulsewidth.
If that fuel is not really needed...it changes the way the engine runs for a split second....and that changes the vacuum, signature...which changes the way the ECU and MPS feed fuel...even worse...which makes fuel enrichment or leaning out...worse....its a fast endless cycle of poor running.
Poor running drops HP and changes vacuum load to the transmission. This causes poor shifting.
Things that must be checked with YOUR system:
1. The valve adjustment must be DEAD ON. Because this is paired injection...two injectors fire every 180* of the distributor.....minute changes in valve adjustment affect the atomization at idle and cause running issues.
2. The small sensor that is crewed into the drivers side head...called TS2...or the head temperature sensor...must have a perfect connection...and must be checked for resistance both when stone cold and when fully warmed up. It has BIG affect on running and driving.
3. This is a fixed fuel pressure system. The ECU has no way of knowing that the pressure is either high or low. It assumes the pressure is correct all the time.
You need to connect an accurate fuel pressure gauge to the ring main between cylinder 3 and 4....and check pressure at idle and when you rev it up. It should be at 28 psi....and should be stable within +/- 1 psi. It should be no higher than 30 psi.
4. Watch the throttle position sensor while the car is idling. If it is moving in and out very slightly even though it is not contacting the arm on the throttle lever...you have a vacuum signature issue. It will either be a leak somewhere in the intake manifold...or variations in vacuum pressure caused by either fuel pressure or ignition timing.
5. These parts..commonly leak vacuum...and cannot be tested wit a smoke test. They simply need to be replaced because they are old.
A. The o-ring between the throttle body and the central intake manifold
B. The rubber boots that connect the central manifold to the intake runners. For now you can clamp them. You clamp the runner end first to keep the boot from sliding off the center manifold...then clamp the center manifold end. Really they should be replaced....but until you decide to replace the gaskets between the runner and cylinder head....start here.
C. the gaskets between the cylinder head and intake runners.
D. The rubber 0-rings on the injector tips. These should be replaced every 3 years when the car is a daily driver...and every 5-7 years even if the car sits still. The best stock seals are available from NAPA under the Echlin brand name.
E. The hoses that go from each head...you should have them....must be absolutely leak free with no cracks. Clamp them at each head. They go to an odd looking central Tee...which is a flame trap. They should be clamped here as well.
F. The other hoses you will have...go from the center manifold to the deceleration valve. This valve may be a manual vacuum valve (which is adjustable) or it may have an electronic relay that is triggered by both vacuum and by a switch that goes to the transmission. We will talk more about this when you verify what you have. But the hoses must be perfect and clamped.
G. There is a hose from the oil chimney to the center manifold...12mm. It has a PCV valve underneath it. It must be perfect an clamped....and when you pull the hose off you can look down into the PCV valve in the oil chimney...make sure it works by attaching a clean piece of hose to it...blow inward...then suck outward. It should lock up when you blow inward.
By this time they are usually cracked and flow in both directions. You cannot buy a new one...but it is an easy fix we will get to later.
H. The small round object with the red wire with the funny boot that goes to the right corner of the center manifold. That is your AAR...auxiliary air regulator...effectively your choke.
It must be open and flowing air when the car is stone cold. Within 5-8 minutes it must not flow any air through it at all. It is electrically heated. The funny boot must be a perfect seal with no vacuum leaks. If its cracked...there are some fixes we will get to later.
I. The fist size thing that looks like a fuel pump on the left side of the engine compartment....is one of the most expensive pieces in the system. That is your manifold pressure sensor. it IS adjustable...but very very time consuming and difficult and not for your mechanic to tinker with unless they have considerable experience with THIS system.
You MUST check it to see if it holds vacuum. Hook a hose up to it and suck on it and put your tongue over the end of the hose. If it leaks down at all....it has either a leaking diaphragm or a bad o-ring.
These cannot be bought new...and rebuilt ones are starting from scratch with adjustment....and cost about $400. But...you can buy a new diaphragm and 0-ring kit now. Check it first for now .
You need to check the four male electrical connector pins for proper resistance. First the outer pair and then the inner pair. The resistance readings are in the book.
NOTE: AS A BARE MINIMUM YOU NEED TO BUY THIS WORKSHOP MANUAL NOW
https://www.amazon.com/Volkswagen-Owners-Workshop-...412+manual
J. The cork gasket on the oil chimney...simply needs to be replaced.
K. There is a special vacuum Tee that goes between teh center manifold and the throttle positioner and the vacuum line to the transmission. All of this must be correct.
6. On the distributor...you need to pull the distributor out....and pull out the set of trigger points from underneath. Clean them and check their resistance and put them back in,. The three wire plug must have perfect connection. These are your fuel injection triggers. You need a spot of synthetic grease on the cam inside.
7. Your timing is jumping around likely because the point plates need to be removed..cleaned...polished on the underside and regreased. Also look to make sure that the pivot points on the weights inside are clean and oiled and both springs are installed.
Also....your timing MUST be set...with vacuum hoses off the vacuum advance unit...to 27* BTDC (the red mark on the fan pulley)...at 3500 rpm.
If the mechanics are trying to time this car at idle...they are total morons and should not be allowed to work on it.
These systems had not the greatest connectors. The connectors and especially the ground connectors that are on the case centerline under the intake plenum...must be pristine.
These items...all of them...and there are a few more that are more advanced for later....are the bare minimum that are required ...anytime you are working on a D-jet injected 40+ year old type 4 car....when it is new to you and running odd or has not been run in a while.
Do not pass go...do not collect $200...do not drive it 10 feet until all of this has been checked.
VERY IMPORTANT:
you need to post some clear pictures...so we can assess the condition of your fuel injection system...so we can help you. Most especially I need to see the back end of the MPS on the left side of the engine compartment...and its part #.
Ray |
|
| Back to top |
|
|
sjbartnik
Samba Member
Joined: September 01, 2011
Posts: 5994
Location: Brooklyn
|
| Posted: Thu Mar 02, 2017 12:36 pm Post subject: Re: No power |
|
|
| bugbenginer wrote: |
- replaced vacuum retard hose, smoke tested for additional vacuum leaks, (intake boot leaking at thermoswitch hose nipple |
Well did they fix that vacuum leak or not?
| Quote: |
-Attempt to check ignition timing but too much bounce to get accurate reading |
Oh yeah. You need to sort that out first. Especially since your injection timing is controlled by the distributor, if you've got a lot of bounce there your injection timing is gonna be all out of whack too.
Basically, whatever Ray says, do it.
_________________
1965 Volkswagen 1500 Variant S
2000 Kawasaki W650 |
|
| Back to top |
|
|
bugbenginer
Samba Member
Joined: December 26, 2012
Posts: 147
Location: boise, id
|
| Posted: Thu Mar 02, 2017 3:18 pm Post subject: Re: No power |
|
|
thank you everyone....
seems like all this may be to much for me, might have to sell....ANY TAKERS 
I will take pics of everything tonight. |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
|
| Posted: Thu Mar 02, 2017 4:30 pm Post subject: Re: No power |
|
|
| bugbenginer wrote: |
thank you everyone....
seems like all this may be to much for me, might have to sell....ANY TAKERS
I will take pics of everything tonight. |
Stop! 
Do you want this car or not? These are far nicer cars than bugs or buses. this is not that hard...and costs very little money.
Its a lot of little stuff. With basic hand tools and for under $100 in parts and gaskets...you can do all of this in an afternoon.
You need to do this yourself....and not take it to a mechanic. There are few if any actually qualified to work on this car.
This is basic tuneup stuff for a D-jet car...and almost 100% of it also must be done to any Porsche 914 and any type 3 fastback or squareback.
Or...you can simply look in the classifieds and buy a set of 32/34 PDSIT carbs and shorty manifolds and switch it carbs. You lose a quick 10hp and a lot of throttle response....but it makes it where any idiot mechanic can work on it.
This is not a car for someone who does not do their own tune-up and wrench work...because A. There are no qualified mechanics for these cars and B. unless you are Bill gates...you cannot afford the rest of the car engine aside.
You do realize that they no longer make shocks and struts for this car right?...or ball joints....or control arm bushings....or radius arm bushings...
We have simple solutions for all of that but...but you will have to do a little light fabbing and your own assembly because no shop is going to know this unless they hang out here...and have done it.
Not trying to scare you off....but a type 4 is not something you pick up on CL...throw $250 and a set of spark plugs at....slam it in an hour and get to go cruising on the strip by the weekend with.
You need to be able to do your own work...unless you are filthy rich...and you need to be serious about it.  Ray |
|
| Back to top |
|
|
KTPhil
Samba Member
Joined: April 06, 2006
Posts: 34002
Location: Conejo Valley, CA
|
| Posted: Thu Mar 02, 2017 4:58 pm Post subject: Re: No power |
|
|
All ACVWs fall into this category, though the Type 4 is probably the furthest on the spectrum (among USA models, anyway). I often say, there are no simple owners anymore, just owner-mechanics. Or broke ex-owners.
But for most of us, it is a labor of love. |
|
| Back to top |
|
|
bodysurfing411
Samba Member
Joined: June 14, 2017
Posts: 4
Location: CA
|
| Posted: Wed Jun 14, 2017 9:53 pm Post subject: Re: No power |
|
|
| Thank you Ray for your wisdom, the info on the clunking rough transmission problem on the 411/412 really helped me!!!.Regret that I bought this beautiful ghost gray,with perfect interior 1971 411.I've got the manuals coming in a week,but I'm trying to get if to the Costa mesa 2017 bug O Rama on Saturday, good thing I live in HB,short drive,thanks,I mean it,Wave Hunter |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21512
Location: Oklahoma City
|
| Posted: Thu Jun 15, 2017 6:43 am Post subject: Re: No power |
|
|
| bodysurfing411 wrote: |
| Thank you Ray for your wisdom, the info on the clunking rough transmission problem on the 411/412 really helped me!!!.Regret that I bought this beautiful ghost gray,with perfect interior 1971 411.I've got the manuals coming in a week,but I'm trying to get if to the Costa mesa 2017 bug O Rama on Saturday, good thing I live in HB,short drive,thanks,I mean it,Wave Hunter |
Ray |
|
| Back to top |
|
|
|
