The Goose: Converting back to Dual Solex PDSIT-32/34

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xyzzy
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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by xyzzy » Sat Jun 09, 2018 11:06 am

Ok.. Quick update.

Went out this morning fresh, after reading everything again. Zero'd out all the mixture screw settings, backing central idle mixture out to 1.5, speed at 4, and each carb to 2.5. With those settings, the bus will not idle with retard hose disconnected (unplugged and open) and central idle disconnected at the solenoid. I have to get out to 3 turns to get it to idle with retard hose disconnected (unplugged and open) and central idle disconnected. At this point, pulling the mixture reference hose stalls. I have to back out carb screws to 4 turns in order to get the car to run with showing a minor drop on the reference hose disconnected.

At the 4 turns out, I have to crank down the central idle mixture to only like 0.75 turns out in order to only get a very slight increase in RPM pulling the mixture hose.

At this stage, the car has low power, and the hesitation is still there.

So, first off, at least my results are consistent. Secondly, I'm confident I followed the directions precisely.

My completely inexperienced estimation is now that because the retard is so substantial, and the timing so retarded, that in order to get through the proper tuning procedure, the carbs mixtures have to be excessively open in order to keep the car running without central idle and retard to compensate for the retarded retard. Does that make sense?

If thats right, then I really need to figure out how to fix the overly retarded retard, to get the correct 10* ATDC at idle, at which point I think I can get through the carb adjustment procedure effectively.

So what's causing the 16*ATDC?
---
1973 Westfalia
Encinitas, California USA

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wcfvw69
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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by wcfvw69 » Sat Jun 09, 2018 6:08 pm

Did you ever reply to the questions about having holes in the throttle plates or not? I don't know anything about those particular carbs. However, I know the German Solex 34-3 carbs can be down right impossible to adjust correctly when mated to the wrong distributor. Basically, they made two main versions of the German Solex 34-3 carb. One to run the DVDA distributor and the other to run the SVDA distributor. The hole in the throttle plate is bigger on the DVDA carb to allow more air at the 5*ATDC timing.

Have you verified that those particular carbs are for your year bus/engine and have the correct throttle plates in them?
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by xyzzy » Sat Jun 09, 2018 8:11 pm

wcfvw69 wrote:
Sat Jun 09, 2018 6:08 pm
Did you ever reply to the questions about having holes in the throttle plates or not? I don't know anything about those particular carbs. However, I know the German Solex 34-3 carbs can be down right impossible to adjust correctly when mated to the wrong distributor. Basically, they made two main versions of the German Solex 34-3 carb. One to run the DVDA distributor and the other to run the SVDA distributor. The hole in the throttle plate is bigger on the DVDA carb to allow more air at the 5*ATDC timing.

Have you verified that those particular carbs are for your year bus/engine and have the correct throttle plates in them?
1) These carbs were the exact carbs that were on this bus since it was built at the factory and sold new. The carbs still have the factory tags on them,
  • Left Carb #021 129 027 P
  • Right Carb #021 129 028 P
2) The 205J DVDA should be the correct one year distributor for the 1973 1700 (right Bill???)

3) I now have a have a 2.0L with hydraulic lifters. Since I now have a 2L, an the 205J was for a 1700, should I be using a different distributor?
satchmo wrote:
Thu Jun 07, 2018 4:41 pm
Humor me a little, if you will. Do you recall if your throttle plates have a small hole in them? Sometimes rebuilt carbs will have plates without the hole, and it should really be in there to let some small amount of air through at idle and creates some of vacuum below the throttle plate. No hole in the plate might actually increase the vacuum below the plate
In terms of the throttle plates, I will email Tim @ Volksbitz and ask him if he remembers, otherwise I'd need to unbolt them from the manifolds and take apart the linkage to look which I will do if he doenst remember. Is there an online reference to use the tags on the carb above to look that up quickly? Ironically I took like a dozen pictures of each carb, from every angle except the bottom -- go figure.

I will try the stop screw adjustment you recommended tomorrow.

Thanks for all your help you guys! I really feel like its close. The only real delta right now I think is the 2.0L engine vs the 1700 from the factory -- everything else I think is correct.....
---
1973 Westfalia
Encinitas, California USA

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by satchmo » Sat Jun 09, 2018 8:55 pm

I took my '73 bus with 1700 cc engine and bumped it up to 2 liter without needing to change the distributor, so doubt that is a problem. Don't think the hydraulic lifters would make any difference either.

You can look at the throttle plates easy enough when you change the intake manifolds around. Maybe you did that already?

Check the gaskets in the 'pizza slice' air horn on top of each carb, and check that there is a good seal from those to the air cleaner box too. The seal around the top to the air filter box needs to be checked as well. The central idle demands a leak free intake for it to work well. You do get a huge sucking sound when you remove the tube that goes from the air filter box to the left air horn at idle, right? Good.

That's all I can think of right now. A little further in on the throttle stop screw on the left might reduce the vacuum signal a hair, and maybe create less retard at the distributor? Total guess on my part. You will reach dual carb nirvana soon, I'm sure.

Satchmo
By three methods we may learn wisdom:
First, by reflection, which is noblest;
second, by immitation, which is easiest;
and third, by experience, which is bitterest. -Confucius

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by xyzzy » Sat Jun 09, 2018 9:48 pm

satchmo wrote:
Sat Jun 09, 2018 8:55 pm
I took my '73 bus with 1700 cc engine and bumped it up to 2 liter without needing to change the distributor, so doubt that is a problem. Don't think the hydraulic lifters would make any difference either.

You can look at the throttle plates easy enough when you change the intake manifolds around. Maybe you did that already?

Check the gaskets in the 'pizza slice' air horn on top of each carb, and check that there is a good seal from those to the air cleaner box too. The seal around the top to the air filter box needs to be checked as well. The central idle demands a leak free intake for it to work well. You do get a huge sucking sound when you remove the tube that goes from the air filter box to the left air horn at idle, right? Good.

That's all I can think of right now. A little further in on the throttle stop screw on the left might reduce the vacuum signal a hair, and maybe create less retard at the distributor? Total guess on my part. You will reach dual carb nirvana soon, I'm sure.

Satchmo
Satchmo: This is great feedback thank you very much. It's good to know someone else has done this successfully.

I haven't swapped the manifolds yet -- the new brake booster balance pipe i have is obstructed and so far I haven't been able to get it unclogged. Soaking in carb cleaner now.

I am missing the gasket on top of the left carb -- I have one on top of the right. I have a replacement on order. The central idle does create a huge sucking sound.

I will try turning in the stop screw on the left and see how it affects the retard at idle.

Thanks again for your help
---
1973 Westfalia
Encinitas, California USA

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wcfvw69
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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by wcfvw69 » Sun Jun 10, 2018 1:59 am

The distributor is matched to the carb/s more than the CC of the engine. Whether it's a 1700 or 2000cc won't matter to the distributor. I would certainly email Tim and pick his brain about the carbs. Maybe he has a suggestion too.

I have another VW buddy struggling with these carbs as well. The things appear to be damn finicky!
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by xyzzy » Sun Jun 10, 2018 8:29 am

satchmo wrote:
Sat Jun 09, 2018 8:55 pm
You can look at the throttle plates easy enough when you change the intake manifolds around. Maybe you did that already?
Image

Was able to look down the throat with a flashlight and verify that there is a hole in the throttle plate.

Per Colin's advice, I pulled the retard from the vacuum can, plugged the hose, and turned idle speed down to 1000 RPMs. Went for a drive and the hesitation/stumble is still there.

Bus runs great on the highway with Colin's settings (Idle Speed: 4.5, Idle Mix: 1.5, Left: 1.5, Right: 1.3).

Hesitation seems to happen right at light throttle. Current thought: Maybe the accelerator cotter pins on the inner most setting are providing too much fuel?
---
1973 Westfalia
Encinitas, California USA

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by Amskeptic » Sun Jun 10, 2018 8:36 am

wcfvw69 wrote:
Sun Jun 10, 2018 1:59 am
I have another VW buddy struggling with these carbs as well. The things appear to be damn finicky!
:cyclopsani: ... to the uninitiated, yes.
BobD - 78 Bus . . . 112,660 miles
Chloe - 70 bus . . . 206,845 miles
Naranja - 77 Westy . . . 121,400 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 91 Lexus LS400 . . . 92,435 miles

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by xyzzy » Mon Jun 11, 2018 3:36 pm

I really butchered the cotter pins trying to get them out of the accelerator pump arm. Right one broke in half. Anyways, got them in the middle hole. Seems like it was running a lot better.. Of course on the test drive, suddenly power dipped a bit and I heard backfiring sounds.. Came to a stop, car stalled. First thought: Central Idle Solenoid. Of course it came unplugged, probably from connecting and disconnecting 50 times....

Tightened the crimp with some pliers, back on the road. Seemed to be better again, then suddenly a new hesitation. Got back to the office looked in the engine compartment and the butchered-half-cotter-pin in the right carb accelerator pump arm fell out. Go figure.

Anyways, got new cotter pins after I realized I could just goto ace hardware for them ( :cheers: :study: ), got them in the middle hole. Seems like its better, but I want to get a cold start in the morning and see as that is when the hesitation is at its worst.

There is still a hesitation,. but I think its much more subtle. I figure I can try the outer holes, but I wanted to get a cold start in the morning and see how it is in the middle holes on an apples to apples comparison to the inner holes.

Tried wrestling a coat hanger into the new balance pipe for an hour to no avail. I'm soaking it in carb cleaner to try and get it unclogged. Unbelievable. Hopefully that will help me clear the obstruction, then its on to the manifold swap.

I feel like it's getting close now for sure! A few weeks ago if an electrical connection came off a carb I'd be calling AAA for a tow -- very thankful for my time with Colin and Robbie, and to all the people on this forum! The VW community is a national treasure.
---
1973 Westfalia
Encinitas, California USA

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by wcfvw69 » Mon Jun 11, 2018 7:20 pm

Nice! I'm glad you're getting so close to having it dialed in correctly. I hope you're on the cusp of getting the engine/carbs running perfect.
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by xyzzy » Tue Jun 12, 2018 6:35 am

wcfvw69 wrote:
Mon Jun 11, 2018 7:20 pm
Nice! I'm glad you're getting so close to having it dialed in correctly. I hope you're on the cusp of getting the engine/carbs running perfect.
Definitely closer now. I got a nice cold start this morning with the accelerator pump cotter pin in the middle holes and the big hesitation/stumble is now a less impactful "stutter". Half way to work I swapped it to the outer most setting, and it seems the stutter is slightly less?

Now I'm wondering if I should redo the PDSIT tuning procedure. The last time I did it with the air cleaner pizza slice arms connected to the carbs and central idle, and the retard hose disconnected at the distributor and left open. I ended up having to back out 3 turns on the carbs to get it to idle without the central idle solenoid and ended up out 4.5 turns after completing the procedure, with the central idle tightened way up (out .75 turns). Perhaps following the instructions clearly (air cleaner arms disconnected from the carbs, the tube on the central idle, and the retard hose disconnected at distributor but plugged would change the outcome.

Currently I'm still at Idle Mixture 1.5, Idle Speed 4.5, Left Carb: 1.5, Right Carb: 1.3
---
1973 Westfalia
Encinitas, California USA

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by Amskeptic » Tue Jun 12, 2018 9:18 am

xyzzy wrote:
Tue Jun 12, 2018 6:35 am
wcfvw69 wrote:
Mon Jun 11, 2018 7:20 pm
Nice! I'm glad you're getting so close to having it dialed in correctly. I hope you're on the cusp of getting the engine/carbs running perfect.
Definitely closer now. I got a nice cold start this morning with the accelerator pump cotter pin in the middle holes and the big hesitation/stumble is now a less impactful "stutter". Half way to work I swapped it to the outer most setting, and it seems the stutter is slightly less?

Now I'm wondering if I should redo the PDSIT tuning procedure. The last time I did it with the air cleaner pizza slice arms connected to the carbs and central idle, and the retard hose disconnected at the distributor and left open. I ended up having to back out 3 turns on the carbs to get it to idle without the central idle solenoid and ended up out 4.5 turns after completing the procedure, with the central idle tightened way up (out .75 turns). Perhaps following the instructions clearly (air cleaner arms disconnected from the carbs, the tube on the central idle, and the retard hose disconnected at distributor but plugged would change the outcome.

Currently I'm still at Idle Mixture 1.5, Idle Speed 4.5, Left Carb: 1.5, Right Carb: 1.3

We are rapidly losing the public interest aspect to the story, because nobody here can guess as to which numbers will yield what results. Also, as per our PM message track, which looks suspiciously identical to this public record, we have some homework assignments lined up which will help make this thread a crisp search, conquer, and victory story. I will state here, as I did in our PM exchange, that we need to do the manifold switch, verify intake integrity and booster behavior, then we will have once again a useful public information thread.
Colin :cyclopsani:
BobD - 78 Bus . . . 112,660 miles
Chloe - 70 bus . . . 206,845 miles
Naranja - 77 Westy . . . 121,400 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 91 Lexus LS400 . . . 92,435 miles

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by xyzzy » Fri Jun 15, 2018 9:58 am

Removed air cleaner and carbs, and swapped manifolds. The left manifold was pretty nasty:

Image

Cleaned it up exquisitely, hooked everything back up. Fired right up. Idle seemed much better, and all cylinders participating equally at idle!

There's still a low RPM / light throttle hesitation/sputter, but the exhaust note sounds pretty amazing. I think it's real close. I am waiting on a new (unclogged) brake booster pipe which should be here next week. I still have a jury-rigged rubber elbow to hose splice job on the current cut pipe, although I'm pretty confident its not leaking, but who knows.

Going to check the timing and see where the idle speed is at later tonight. Was at 780 with a barely-participating #3 prior. Carb settings still the same.

Super excited I was able to take this all apart and put it all back together myself. Getting quite the education!
---
1973 Westfalia
Encinitas, California USA

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by satchmo » Fri Jun 15, 2018 11:07 am

Awesome!

FWIW, I used 90 degree spark plug boots for the elbows to the brake booster pipe. You can find a selection at any auto parts store. Way better than any repo stuff I could find. You do not want to risk having those elbows crack and leak as it will burn up a cylinder in a hurry. I got tired of worrying about that and used the spark plug boots instead.

Satchmo
By three methods we may learn wisdom:
First, by reflection, which is noblest;
second, by immitation, which is easiest;
and third, by experience, which is bitterest. -Confucius

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Re: The Goose: Converting back to Dual Solex PDSIT-32/34

Post by xyzzy » Fri Jun 15, 2018 11:20 am

satchmo wrote:
Fri Jun 15, 2018 11:07 am
Awesome!

FWIW, I used 90 degree spark plug boots for the elbows to the brake booster pipe. You can find a selection at any auto parts store. Way better than any repo stuff I could find. You do not want to risk having those elbows crack and leak as it will burn up a cylinder in a hurry. I got tired of worrying about that and used the spark plug boots instead.

Satchmo
This is great feedback thanks Satchmo. I did get a set of what I believe are pretty good quality german elbows -- I'll post a pic and see what you think. As soon as I get this new carb set up dialed in and my brake booster fixed, I really want to add a CHT and Oil Temp gauge. It seems that the Dakota Digital CHT gauge is the way to go, what about for Oil Temp? Is the Dakota Digital oil temp gauge good as well? Figured may as well get a matching set.
---
1973 Westfalia
Encinitas, California USA

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