412 Engine and Transmission Renew/Rebuild with pics

[raygreenwood]

Actually your runners look fairly normal. ...as runner alignment goes.

Typically just make sure that the plenum is bolted up to the case and standing as straight as possible. Jim Adney is pretty close.

Before you put any, sealer on the phenolic blocks or runner to head joints, go ahead and bolt things up dry.
Looking at vertical alignment of runner tube to spigot....its always been fairly easy to either lean on or pull on the runners a little at a, time to affect vertical alignment.

As for front and back....ranges from pushing/pulling to pushing a, wooden wedge between them or between the runner and case.

Once you get it reasonably close......I remove the runners from thr head again and check everything c and add sealant if necessary. Ray

[Lahti411]

Sorry, just a short note as im writing from mobile phone.
Atleast the manual transmission is easier to install together with the engine. It's quite difficult to squeeze the engine into the body opening with the transmission in place. I've done that couple of times but always thought it would have been easier just to lift the whole chunk in one piece...
_________________
My cars: 1972 VW 411 Variant; 1973 VW 412 4d sedan

[raygreenwood]

[ClassicCamper]

Well, despite the 95+ degree weather, I was able to get back into the motor. Its finally starting to look like an engine:

I was able to slightly bend the intake runners to match the receiving end of the plenum. Although the intake runner to plenum seals from B** Dep*t were a great fit, the fabric on the end frays if you even breathe on it. I secured them with tie wraps. You can't even move them by hand. Very tight. Injectors and fuel rails installed tonght. I'm presuming that the alternator wires leading to the starter go throuh the lowest hole on the right side of the vertical tin next to the flex plate. Is that correct? I fed it through a rubber grommet.

One other question. Is this the way the fuel pressure regulator goes? It was just hanging there when I got the car, so this is how I rigged it up:

Also, as a side note, this table jack from Harb** Freigh* works very well:

Also, per Lars' suggestion, I ordered the vacuum hose set. i'll let you know how I like it upon arrival. Its really for the 914, but close enough. Thanks again, -Ron

[raygreenwood]

Everything is looking good. Find some thin hose clamps for the runner boots. The wire tires will fail. With age and beat, the boots will start to leak.

I take the runner boots and all fabric covered hoses.....and take a piece of masking tape and wrap it around the hose about 1/2" from the cut end. Take an acid flux brush, glue applicator bruah or stiff paint brush with bristles cut short.....and take a dab of Permatex ultra....gray or black works fine......and paint it on....working it into the hose cloth, lapping over the cut end. Remove the tape before it tacks up. The hoses will not fray, itlooks clean, and makes a great seat for hose clamps. Ray

[ClassicCamper]

So, here is the before picture: (taken end of June)

Now after: (taken Aug 11)

If it runs as good as it looks, I'm in good shape. I still need to figure out how to hold the gear shift linkage mounting bracket to the trans and adjust it. The trans rebuilder accidentally lost the two bolts that hold the bracket on and the nut that pinches the cable in. If anyone is under his/her car this weekend and can PM me a pic of linkage, it would be greatly appreciated.

I need to recheck all of my connections, make sure everything is tight, mount fuel pump, and install the muffler. Hoping to get this done tomorrow. Also, I've been combing around for ANY solidified info how to properly adjust this throttle kicker to no avail:

At this point, I'd settle for a 'you are in the ball park!'

Thanks to the samba crew for getting me this far. I would not have been able to be here without your help. The books in market are just too vague and sketchy. I hope I'll be able to pay forward all the knowledge you have shared with me.

[raygreenwood]

I will find you what I have on the throttle kicker. Ray

[Lars S]

Nice work Ron! Looking forward to follow this.


/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

[ClassicCamper]

Thanks Lars. Today may be the big day.

[raygreenwood]

Within an hour I will post all of the adjusting specs I have on the throttle kicker from the ojly three books I can find it in.

Oddly.... ....and you learn something new every day.....I had no idea that the 1.8L engine with L-jet in the 1975-1976 buses....used the same throttle kicker. The Haynes manual for the bus actually has the best adjusting info. More to come. Ray

[raygreenwood]

Here are all the specs I could find for the throttle kicker adjustment:

Ignore the parts you dont need as I am posting all sections in order as each book lists them.

Chiltons VW 1970-81 manual:

Haynes 411-412 manual (green)

Haynes VW transporter manual 1972-1979

The details are this:

You will note in the text that there are differences in idle speed adjustment from early to late and from 411/412 and the bus.

This is most probably due to differences in lockup/decoupling point of the torque converters installed...and possibly somewhat due to the ignition mechanical advance...but less so due to advance because all of these idle speeds should be below the mechanical advance kick in point.

1. The car must be in drive with the engine on to load the torque converter.

2. The handbrake should be on TIGHT....and i would block the wheels as well.

3. Connect a tachometer . Idle speed should be set to spec.....and engine warmed up....and timing correct.

4. Increase idle speed by opening the throttle....you only need a couple of hundred rpm increase.....then drop the throttle closed.

If...as the text notes.....the idle speed drops too low ...meaning below the set point you had the idle set to...and is trying to stall....
.....adjust the gap between the kicker screw and the throttle lever...a little closer to the throttle lever so that it holds the throttle open for just a little longer/farther ...until idle stabilizes.

If the kicker does not move...or moves in out out...oscillates...you have a vacuum leak somewhere. The TB seal can do this....or the throttle kicker itself can be leaking.

Ray

[ClassicCamper]

That kicker adjustment worked like a charm. Thanks. That procedure wasn't in my green Haynes manual, but I believe mine is a 1975 edition.

Transmission question: Car shifts very early from 1 to 2. The shift occurs just under 20 MPH. Also, 2-3 shift occurs a bit high, around 40-45 MPH. Is there an easy way to adjust this? Can I remove the vaccuum hose at tranny and adjust from there?

I have a bus shop manual, so I'm going to see if i can find any info there. Any feedback would be appreciated.

[raygreenwood]

What is happening...sounds like either ...as you noted. ..a modulator adjustment ......which is either needed because vacuum signature is different than needed or becausd the main pressure controlled by the modulator is different.

If you have it.....look in the Brown type 3 Bentley in the auto trans section. Really it would be worthwhile to put the gauges on the trans and do the driving test and adjust pressures.

You "can" do pretty good work by driving and testing and just tweaking until it drives better. Ray

[ClassicCamper]

Thanks to Ray, I was able to get her running like a champ. (Almost). It accelerates quickly and cruises very nice. Amazed how much power this little car has. I do have a nagging issue though: terrible idle when stopped in drive. Here is what I've checked/adjusted

- Points
- Valves
- Timing
- All vaccum lines
- Throttle kicker
- Checked grounds

So, I adjusted the throttle kicker to .20 gap while car was idling in park. Once I put it into gear, the car was fighting against itself. As it began to stall, the kicker opened the throttle and began a vicious cycle against itself making the idle surge really bad. So, I backed off the kicker until I find this problem.

The issue still remains: when I'm stopped at a light in Drive, the car surges forward and then the idle drops suddenly, almost to a stall. Sometimes, it will not surge, just a rough idle. On occasion, it will stall out all together. I put a tach on it and adjusted the idle to spec, to no avail. The gray knob on the ECU is turned all the way to the right (clockwise). Any attempts to move it counter clockwise will cause the engine to idle more erratically and will stall out car after about the 5th click.

Note: If Im stopped at a light and put it in Neutral or Park, the car idles fine with maybe a slight erratic idle. Hardly noticable though.

Any ideas?

[raygreenwood]

Yes....if your gray knob is all the way in one direction at idle...which is the only time it has any jnput......then your main fuel mixture is still off.

There are other items....but very hard to track. The REAL issue with the type 4.....with D-jet....and with the automatic trans.....is the low stall point of the converter.

If you idle up to say around 925-950 rpm...which will fix this....you will be constantly straining against the brake. The kicker is designed for the final few feet of deceleration to keep the engine idling until the converter uncouples.

Idling down to about 800.....stops the issue....but your main fuel mixture must be spot on....or the idle will drop low enough thatvacuum drops low and it engages the kicker which causes a surge....which causes the cyle you have.

Before you go further....i would suggest if you have not done so....to grab the brown bentley type 3 manual.....and adjust the bands and main atf pressure. Make sure the trans is working its best.

Then you need to make sure your CHT is not dropping too low....even if it takes a ballast resistor......and finally adjust the center MPS load screw.....not the outer full load stop screw.....you adjust that later....after you have adjusted main fuel mixture....in cycles.

You adjust the main mixture slightly. ....drive......then at idle work the gray knob back a click. Adjust idle again at the tB.....then Adjust the center mixture screw again.....drive.....then adjust the gray knob another click....correct idle....repeat.

Unless you use a fixed resistor IN PLACE of the CHT...while doing this.....you may have to let the car cool between adjustments. It takes all day.

When you have good driving, the gray knob centered....a decent idle.....and it,WILL still run crappy off the line when you have this done.....only then do you fix the off the line issues by adjusting the outer full load stop.

Later...you may need to do some slight tweaking to the vacuum retard and advance as we discussed. Ray

[ClassicCamper]

There is no condition of idle that seems to stop this surge. I'll double-check when I'm home tomorrow. It does feel like the transmission is 'engaging' and releasing at idle causing this surge. It gets to the point at operating temperature (after a long freeway drive) that the surge gets so severe, it will stall. I find myself having to hit the brake harder to keep it from lurching forward.

If I adjust the throttle kicker to spec, it will 'kick' throttle open and than retract over and over. Making even a stronger surge. Hopefully, I can post a you tube video at some point.

[raygreenwood]

No need to post a video....I have seen this cycle many times.

There are a couple of items from our discussions that are partly to blame for this.

1. Your overall vacuum level at idle is LOW. This is partly due to the level of tuning (which will not improve until you can get the idle straight enough to properly tune the MPS)...and mostly to do with the low compression pistons installed....and having an MPS that is tuned for a high compression system.

Why is this critical? Think of how the kicker works. Its designed to be retracted by vacuum. If your vacuum is low...its not retracted well enough. That means that its actual extended length is probably incorrect because of how they have you adjust it....specific gap between kicker bolt and throttle lever...at idle.


That means that when vacuum is fully released by any opening of the throttle...your foot or the kicker....the kicker over extends...opening the throttle too far.....you get a nasty idle spike.....the kicker retracts....the idle dies down quickly...creating a lean spike.....which is excessive air and deficit of fuel....car tries to stall....already low vacuum drops....kicker extends....cycle repeats.

Its also very common that the kicker leaks down. Test it wit ha vacuum pump. Vacuum it down and hold. If it leaks and extends...it may never work correctly.

2. You can adjust the Kicker a little bit by moving the spring retainer to less tension on the rod so that it requires less vacuum to keep sucked in.

You have to remember that every part on this engine was set up from the factory for high compression...and now you have low compression. It will take some tuning to get around that.

One thing that can help....is to put an inline restrictor in the vacuum line to the kicker. If its not leaking It will slow down the vacuum build...and also slow down the vacuum release.....which can help when you have less manifold vacuum to start with. Since its likely a 3mm vacuum line....take a piece of 3mm nylon bolt or thread rod...drill a 0.5 mm hole through the center and stuff it in the line and reconnect it.
You cn alwasy make the hole larger later but start small.

Also....did you do the PCV valve modification? (cant remember of yours had one but it should).....the PCV valve is a major problem for the kicker and vacuum levels.

3. What I would do...and have had to do in the past....to get the MPS properly tuned....is remove the kicker and plug the line. Idle the car up into the 900 rpm range so it does not stall on stopping. You will have to adjust your idle timing accordingly.

Then install the CHT resistor for tuning and get back to adjusting the MPS properly. Once you know the MPS is correct and your fuel mixture is perfect for all driving ranges...then get back to the drivability issues.

Also...once the MPS is adjusted......you need to get the transmission adjusted. Ray

[ClassicCamper]

So, here is where I'm at: my wits end.

This is what I've done in an effort to fix the rough idle and occasional stalling condition when engine at operating temperature only. If I take a quick run to the store (abt 4-5 miles each way) car is fine. After a freeway run, stall condition begins. Steps taken:

1) Installed resistor between CHTS and FI harness. Result: slightly brought idle up, but nothing substantial. Engine still wanted to stall when hot and in gesr. It did make the car easier to start cold, however.

2) Installed an inline reducer in PCV line with a 2.5-3mm orifice. Result: Engine ran worse. Acceleration was choppy too.

3) Checked all hoses again, no known leaks.

4) Throttle kicker: Adjusted according to specs per specs above. Result: heavy surges when idling in gear.

5) Adjusted tension spring on kicker. Result: idled in gear better, but would eventually stalls.

6) Adjusted idle per specs above. 850 and then set kicker to operate when engine dips below 650 RPM.

I running out of ideas here. Any help would be greatly appreciated.

Side note: the SLIGHTEST touch of the pedal when hot virtually eliminates the issue. I may have some slight surging past 50 MPH; its hard to notice and may even be the effect of the wind.

[raygreenwood]

[ClassicCamper]

The resistor is the one you said to put inline with the CHTS I believe it's 150 :

1) Should I install that and leave it there for now (in-line)?

2) I'll put the 3mm fixed orifice restrictor in-line and remove the pcv valve. Note: The PCV valve in the car now does block vacuum when you either suck or blow on it (I forget now)

I know these changes are for the greater good, so I'll make them. Double check valves, timing, points gap, etc.

I plan on taking a long drive this evening, so I'll report back. I'll settle with the rough idle, it's the stalling that is really annoying me..