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soggz
Samba Member
Joined: November 04, 2007
Posts: 33
Location: Zummerzet
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 Posted: Mon May 05, 2025 10:43 pm Post subject: Bocar pict 34 3 woes |
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| Hi all. Just cleaned up and rebuilt one, put it back on my 1600tp, but I seem to have this flat spot I can’t shift. Done all the valves and timing as well as I can, but on pulling away , the van just bogs down if I’m too ‘heavy footed’. Seems to run fine, after the initial pull away. Was wondering if it was the dizzy, as it’s pretty old. ( no idea). I rebuilt the engine last year with new bearings etc, and runs sweet, fires up first time, etc, but idles fast. I have no tachyometer, just a cheapo timing light. Been all around it trying to source air leeks, but no change in engine tone when squirting carb cleaner about. I’m a bit confused on it all. Had the van since 2006. Tia. |
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wagen19
Samba Member
Joined: November 16, 2007
Posts: 565
Location: germany
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| Posted: Tue May 06, 2025 1:02 am Post subject: Re: Bocar pict 34 3 woes |
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| soggz wrote: |
| Hi all. Just cleaned up and rebuilt one, put it back on my 1600tp, but I seem to have this flat spot I can’t shift. Done all the valves and timing as well as I can, but on pulling away , the van just bogs down if I’m too ‘heavy footed’. Seems to run fine, after the initial pull away. Was wondering if it was the dizzy, as it’s pretty old. ( no idea). I rebuilt the engine last year with new bearings etc, and runs sweet, fires up first time, etc, but idles fast. I have no tachyometer, just a cheapo timing light. Been all around it trying to source air leeks, but no change in engine tone when squirting carb cleaner about. I’m a bit confused on it all. Had the van since 2006. Tia. |
Make sure, you have the correct dizzy in a perfect condition. Vacuum advance must be easy going. Als one drop of oil inside the shaft can help. |
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soggz
Samba Member
Joined: November 04, 2007
Posts: 33
Location: Zummerzet
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| Posted: Tue May 06, 2025 4:34 am Post subject: Re: Bocar pict 34 3 woes |
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| wagen19 wrote: |
| soggz wrote: |
| Hi all. Just cleaned up and rebuilt one, put it back on my 1600tp, but I seem to have this flat spot I can’t shift. Done all the valves and timing as well as I can, but on pulling away , the van just bogs down if I’m too ‘heavy footed’. Seems to run fine, after the initial pull away. Was wondering if it was the dizzy, as it’s pretty old. ( no idea). I rebuilt the engine last year with new bearings etc, and runs sweet, fires up first time, etc, but idles fast. I have no tachyometer, just a cheapo timing light. Been all around it trying to source air leeks, but no change in engine tone when squirting carb cleaner about. I’m a bit confused on it all. Had the van since 2006. Tia. |
Make sure, you have the correct dizzy in a perfect condition. Vacuum advance must be easy going. Als one drop of oil inside the shaft can help. |
Thanks for the reply. The dizzy I have is a AJ. Not sure if it is the right one, tbh, or weather it works great. I have ordered a new one and plugs lead coil, yesterday, for a 1600tp from Just Kampers. I am hoping that will help solve my problem with it. |
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kreemoweet
Samba Member
Joined: March 13, 2008
Posts: 4074
Location: Seattle, WA
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| Posted: Tue May 06, 2025 8:05 am Post subject: Re: Bocar pict 34 3 woes |
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Flat spots such as you describe can be caused by improperly adjusted/malfunctioning accelerator pump on the carb. Did you test/adjust that
per the procedure in your Bentley manual?
Your fast idle would indicate you haven't adjusted the carb idle settings, again as outlined in your Bentley manual.
You cannot tune or properly maintain your bus without a minimum of basic tools, which includes a tach.
_________________
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wagen19
Samba Member
Joined: November 16, 2007
Posts: 565
Location: germany
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| Posted: Tue May 06, 2025 9:29 am Post subject: Re: Bocar pict 34 3 woes |
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| kreemoweet wrote: |
Flat spots such as you describe can be caused by improperly adjusted/malfunctioning accelerator pump on the carb. Did you test/adjust that
per the procedure in your Bentley manual?
Your fast idle would indicate you haven't adjusted the carb idle settings, again as outlined in your Bentley manual.
You cannot tune or properly maintain your bus without a minimum of basic tools, which includes a tach. |
OK, imo you are just right so far.
As I understand, he has probably a rather fresh or new aftermarket Bocar carb, but a rather old, tired and possibly wrong dizzy from an AJ Beetle engine. (probably 043 905 205 H, 5° ATDC, shifter, or 043 905 205 J, Automatic 0° at TDC)
So the issues here can also be caused by a late starting, "lazy" or tired ignition advance (imo).
Imo the single vacuum dizzies with ignition 7,5 ° BTDC are better.
Suggest Bus dizzies 211 905 205 S, or 043 905 205 B, or 043 905 205 L, if available. ZZP ignition 7,5° before TDC static or when idling at 850 rpm without vacuum hose connected.
Also possible are Beetle dizzies 043 905 205 and 205 A.
Good luck! |
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OB Bus
Samba Member
Joined: February 09, 2003
Posts: 2678
Location: Ocean Beach - San Diego
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| Posted: Tue May 06, 2025 10:42 am Post subject: Re: Bocar pict 34 3 woes |
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And if the proper carb does not solve your problems, the issue may be that Bocar.
Get your self a rebuilt Solex34 PICT from Volkzbitz oil these forums. You will likely be much happier.
_________________
Larry in OB
Stop dead photo links! Post your photos to The Samba Gallery!
69 Westfalia and 2002 Eurovan Camper.
People deserve the Government they voted for. |
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mikedjames
Samba Member
Joined: July 02, 2012
Posts: 3265
Location: Hamble, Hampshire, UK
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| Posted: Tue May 06, 2025 10:55 am Post subject: Re: Bocar pict 34 3 woes |
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Probably worth spending on something with a rev counter - a cheap automotive digital voltmeter might be good.
If it is idling fast, the distributor will be permanently adding timing advance, so that if you set the timing to 8 degrees at "idle" you actually end up setting the true idle setting as slightly retarded relative to where it should be.
A good start point is to get it to rev up to where the timing does not advance and then set it to 28 degrees instead. What happens at idle does not matter at first.
Check that the choke is coming off and that when you blip the throttle with the choke off, the fast idle cam drops down so the fast idle screw is not touching the cam.
If its idling fast still, then turn down the idle air flow screw until its in the ballpark and adjust mixture for lean best idle, aiming at 850 rpm, may have to repeat it.
Usually if there are air leaks, you can hear the harsh hissing, the carburettor
tends to make a more muted roar.
On my Bocar, the spindle bushings had worn out, and I was able to bodge in some bushings intended for a Solex with some epoxy glue taking up the gap between the bushings and the carburettor body.
What also does not help is when people take off the stock air cleaner and fit a crude air filter on top - this means you end up with cold air going into the carburettor, the effect is to lean out the mixture and potentially add to flat spots.
In the end, I fitted a Weber 32/36 progressive but kept the stock uncool looking oil bath air cleaner for hot air, and used a PLX Devices Air Fuel Ratio meter for tuning. This has been pretty good over the last ten years or so.
_________________
Ancient vehicles and vessels
1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.
1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy |
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airschooled
Air-Schooled
Joined: April 04, 2012
Posts: 13413
Location: West Coast, USA
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| Posted: Tue May 06, 2025 10:57 am Post subject: Re: Bocar pict 34 3 woes |
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| OB Bus wrote: |
And if the proper carb does not solve your problems, the issue may be that Bocar.
Get your self a rebuilt Solex34 PICT from Volkzbitz oil these forums. You will likely be much happier. |
Another vote for Volkzbitz.
A side note, new "stock" mufflers have lazy preheat plumbing. (The mufflers are just built wrong compared to OG. See how the heat riser flow doesn't exit with the flow of exhaust gas? The heat risers don't even get hot on the freeway…) This German 34pict3 I worked on would NOT accelerate smoothly even with gratuitous accelerator pump discharge. Freezing cold intake manifold… Repairing the stock air cleaner preheat valve brought back smooth acceleration, and I was able to dial the accelerator pump adjustment back.
I just wish the people spec'ing parts owned tape measures and eyeballs, much less micrometers…
Robbie
Muffler in question, doesn't get very hot:
NOS bus muffler from EB's gallery:
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OB Bus
Samba Member
Joined: February 09, 2003
Posts: 2678
Location: Ocean Beach - San Diego
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| Posted: Tue May 06, 2025 11:22 am Post subject: Re: Bocar pict 34 3 woes |
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| airschooled wrote: |
Muffler in question, doesn't get very hot:
|
I think I recognize that bus!
With the preheat tube in place and functioning that engine runs smooth and great!
_________________
Larry in OB
Stop dead photo links! Post your photos to The Samba Gallery!
69 Westfalia and 2002 Eurovan Camper.
People deserve the Government they voted for. |
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heimlich 
VWNOS.com
Joined: November 20, 2016
Posts: 7420
Location: Houston, Texas
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| Posted: Tue May 06, 2025 4:23 pm Post subject: Re: Bocar pict 34 3 woes |
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Try running the Bocar without the retard hose attached. Also plug it at the carburetor. Time it as you would an SVDA, 7.5 at idle and 850 or so.
I have some NOS factory Bocar units in the box if you want.
_________________
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Classic Brands. Classic Quality.
Not all parts are made the same. NOS OE/OEM parts made mainly in West Germany, Early Germany, and Early Brazil are where VW produced the best quality parts and best fitting products.
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wagen19
Samba Member
Joined: November 16, 2007
Posts: 565
Location: germany
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| Posted: Tue May 06, 2025 10:36 pm Post subject: Re: Bocar pict 34 3 woes |
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| OB Bus wrote: |
And if the proper carb does not solve your problems, the issue may be that Bocar.
Get your self a rebuilt Solex34 PICT from Volkzbitz oil these forums. You will likely be much happier. |
A engine can only run properly, when it´s:
1.) mechanical sound
2.) ignition OK (at idling and up to the whole range of rpm)
3.) carb or injection system OK
4.) exhaust also OK
All and everything must be OK!
A new perfect carb or distributer alone is no match maker.
AND: the carb and dizzy must match, work together (vacuum range) |
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soggz
Samba Member
Joined: November 04, 2007
Posts: 33
Location: Zummerzet
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| Posted: Wed May 07, 2025 12:11 am Post subject: Re: Bocar pict 34 3 woes |
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| wagen19 wrote: |
| kreemoweet wrote: |
Flat spots such as you describe can be caused by improperly adjusted/malfunctioning accelerator pump on the carb. Did you test/adjust that
per the procedure in your Bentley manual?
Your fast idle would indicate you haven't adjusted the carb idle settings, again as outlined in your Bentley manual.
You cannot tune or properly maintain your bus without a minimum of basic tools, which includes a tach. |
OK, imo you are just right so far.
As I understand, he has probably a rather fresh or new aftermarket Bocar carb, but a rather old, tired and possibly wrong dizzy from an AJ Beetle engine. (probably 043 905 205 H, 5° ATDC, shifter, or 043 905 205 J, Automatic 0° at TDC)
So the issues here can also be caused by a late starting, "lazy" or tired ignition advance (imo).
Imo the single vacuum dizzies with ignition 7,5 ° BTDC are better.
Suggest Bus dizzies 211 905 205 S, or 043 905 205 B, or 043 905 205 L, if available. ZZP ignition 7,5° before TDC static or when idling at 850 rpm without vacuum hose connected.
Also possible are Beetle dizzies 043 905 205 and 205 A.
Good luck! |
Hi. My bocar carb has probably only done around 2000 miles. I rebuilt it a couple of weeks ago, as I replaced my fuel tank which kept blocking the carb with rust from it. I will take the carb off and go through it again. |
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soggz
Samba Member
Joined: November 04, 2007
Posts: 33
Location: Zummerzet
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| Posted: Wed May 07, 2025 12:14 am Post subject: Re: Bocar pict 34 3 woes |
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| mikedjames wrote: |
Probably worth spending on something with a rev counter - a cheap automotive digital voltmeter might be good.
If it is idling fast, the distributor will be permanently adding timing advance, so that if you set the timing to 8 degrees at "idle" you actually end up setting the true idle setting as slightly retarded relative to where it should be.
A good start point is to get it to rev up to where the timing does not advance and then set it to 28 degrees instead. What happens at idle does not matter at first.
Check that the choke is coming off and that when you blip the throttle with the choke off, the fast idle cam drops down so the fast idle screw is not touching the cam. I will try and get a rev counter. As for air leaks. If I put my hand on top of the carb, it just sucks my hand in and stalls. I don’t hear any sucking noises from anywhere else.
If its idling fast still, then turn down the idle air flow screw until its in the ballpark and adjust mixture for lean best idle, aiming at 850 rpm, may have to repeat it.
Usually if there are air leaks, you can hear the harsh hissing, the carburettor
tends to make a more muted roar.
On my Bocar, the spindle bushings had worn out, and I was able to bodge in some bushings intended for a Solex with some epoxy glue taking up the gap between the bushings and the carburettor body.
What also does not help is when people take off the stock air cleaner and fit a crude air filter on top - this means you end up with cold air going into the carburettor, the effect is to lean out the mixture and potentially add to flat spots.
In the end, I fitted a Weber 32/36 progressive but kept the stock uncool looking oil bath air cleaner for hot air, and used a PLX Devices Air Fuel Ratio meter for tuning. This has been pretty good over the last ten years or so.
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soggz
Samba Member
Joined: November 04, 2007
Posts: 33
Location: Zummerzet
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| Posted: Wed May 07, 2025 12:18 am Post subject: Re: Bocar pict 34 3 woes |
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| soggz wrote: |
| mikedjames wrote: |
Probably worth spending on something with a rev counter - a cheap automotive digital voltmeter might be good.
If it is idling fast, the distributor will be permanently adding timing advance, so that if you set the timing to 8 degrees at "idle" you actually end up setting the true idle setting as slightly retarded relative to where it should be.
A good start point is to get it to rev up to where the timing does not advance and then set it to 28 degrees instead. What happens at idle does not matter at first.
Check that the choke is coming off and that when you blip the throttle with the choke off, the fast idle cam drops down so the fast idle screw is not touching the cam. I will try and get a rev counter. As for air leaks. If I put my hand on top of the carb, it just sucks my hand in and stalls. I don’t hear any sucking noises from anywhere else.
If its idling fast still, then turn down the idle air flow screw until its in the ballpark and adjust mixture for lean best idle, aiming at 850 rpm, may have to repeat it.
Usually if there are air leaks, you can hear the harsh hissing, the carburettor
tends to make a more muted roar.
On my Bocar, the spindle bushings had worn out, and I was able to bodge in some bushings intended for a Solex with some epoxy glue taking up the gap between the bushings and the carburettor body.
What also does not help is when people take off the stock air cleaner and fit a crude air filter on top - this means you end up with cold air going into the carburettor, the effect is to lean out the mixture and potentially add to flat spots.
In the end, I fitted a Weber 32/36 progressive but kept the stock uncool looking oil bath air cleaner for hot air, and used a PLX Devices Air Fuel Ratio meter for tuning. This has been pretty good over the last ten years or so.
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Hello Mike, hope all is well. Long time an all that. I don’t have a rev counter. Probably a good idea to get one. As you know, I rebuilt the engine, I recently had to take it and the gearbox out out to replace the nose come seal. While I had it all out I replaced the fuel tank as it was full of rust, hence the carb blocking. I’ve cleaned and rebuilt the carb and am now getting this trouble with it. I’m a bit stuck, as I have done everything per the manuals. |
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soggz
Samba Member
Joined: November 04, 2007
Posts: 33
Location: Zummerzet
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| Posted: Wed May 07, 2025 5:29 am Post subject: Re: Bocar pict 34 3 woes |
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| wagen19 wrote: |
| OB Bus wrote: |
And if the proper carb does not solve your problems, the issue may be that Bocar.
Get your self a rebuilt Solex34 PICT from Volkzbitz oil these forums. You will likely be much happier. |
A engine can only run properly, when it´s:
1.) mechanical sound
2.) ignition OK (at idling and up to the whole range of rpm)
3.) carb or injection system OK
4.) exhaust also OK
All and everything must be OK!
A new perfect carb or distributer alone is no match maker.
AND: the carb and dizzy must match, work together (vacuum range) |
I agree. Everything I have done on the engine is standard and up to spec. I’m not sure about the dizzy, as it’s pretty old. The engine, I rebuilt from a beetle AR case, with new bearings after an align bore. The thrust bearing was recut. I then used my newish 1600 barrels and pistons from my old engine. The dizzy is a AJ dizzy so I am not sure if it combatable with a picture 34 3, as the engine had a little Empi carb on it when I got it. I used my Pict 34 after I cleaned it and rebuilt it. I’m waiting on a new dizzy to turn up. |
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wagen19
Samba Member
Joined: November 16, 2007
Posts: 565
Location: germany
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| Posted: Wed May 07, 2025 5:49 am Post subject: Re: Bocar pict 34 3 woes |
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| soggz wrote: |
| wagen19 wrote: |
| OB Bus wrote: |
And if the proper carb does not solve your problems, the issue may be that Bocar.
Get your self a rebuilt Solex34 PICT from Volkzbitz oil these forums. You will likely be much happier. |
A engine can only run properly, when it´s:
1.) mechanical sound
2.) ignition OK (at idling and up to the whole range of rpm)
3.) carb or injection system OK
4.) exhaust also OK
All and everything must be OK!
A new perfect carb or distributer alone is no match maker.
AND: the carb and dizzy must match, work together (vacuum range) |
I agree. Everything I have done on the engine is standard and up to spec. I’m not sure about the dizzy, as it’s pretty old. The engine, I rebuilt from a beetle AR case, with new bearings after an align bore. The thrust bearing was recut. I then used my newish 1600 barrels and pistons from my old engine. The dizzy is a AJ dizzy so I am not sure if it combatable with a picture 34 3, as the engine had a little Empi carb on it when I got it. I used my Pict 34 after I cleaned it and rebuilt it. I’m waiting on a new dizzy to turn up. |
A new aftermarket dizzy can be totally junk!
Many of them make 40 to 45° BTDC when static at 7,5°. For me, a absolute NO GO!
Imo, a good used original or a restored one is the very best choice. |
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 52107
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| Posted: Wed May 07, 2025 6:59 am Post subject: Re: Bocar pict 34 3 woes |
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Set your timing at 30-32° BTDC @3800+ rpm, hose(s) off and plugged. This will mimic high rpm, full throttle operation when you are asking the most from your engine. It also eliminates the effects of a high idle on your timing that mikedjames mentioned. Do not reattach the retard hose if the retard can will not hold vacuum, just leave it plugged off.
You should be able to see an instantaneous spray of fuel into the throat of the carb when you blip the throttle. Only takes three hands to do.  |
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wagen19
Samba Member
Joined: November 16, 2007
Posts: 565
Location: germany
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| Posted: Wed May 07, 2025 7:59 am Post subject: Re: Bocar pict 34 3 woes |
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| Wildthings wrote: |
Set your timing at 30-32° BTDC @3800+ rpm, hose(s) off and plugged. This will mimic high rpm, full throttle operation when you are asking the most from your engine. It also eliminates the effects of a high idle on your timing that mikedjames mentioned. Do not reattach the retard hose if the retard can will not hold vacuum, just leave it plugged off.
You should be able to see an instantaneous spray of fuel into the throat of the carb when you blip the throttle. Only takes three hands to do. |
Imo, this is a perfect way to adjust ignition with a defective or wrong dizzy 1000 miles far away from home.
When original a vacuum dizzy is installed, it should be the better way, going original. |
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soggz
Samba Member
Joined: November 04, 2007
Posts: 33
Location: Zummerzet
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| Posted: Wed May 07, 2025 8:08 am Post subject: Re: Bocar pict 34 3 woes |
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| wagen19 wrote: |
| soggz wrote: |
| wagen19 wrote: |
| OB Bus wrote: |
And if the proper carb does not solve your problems, the issue may be that Bocar.
Get your self a rebuilt Solex34 PICT from Volkzbitz oil these forums. You will likely be much happier. |
A engine can only run properly, when it´s:
1.) mechanical sound
2.) ignition OK (at idling and up to the whole range of rpm)
3.) carb or injection system OK
4.) exhaust also OK
All and everything must be OK!
A new perfect carb or distributer alone is no match maker.
AND: the carb and dizzy must match, work together (vacuum range) |
I agree. Everything I have done on the engine is standard and up to spec. I’m not sure about the dizzy, as it’s pretty old. The engine, I rebuilt from a beetle AR case, with new bearings after an align bore. The thrust bearing was recut. I then used my newish 1600 barrels and pistons from my old engine. The dizzy is a AJ dizzy so I am not sure if it combatable with a picture 34 3, as the engine had a little Empi carb on it when I got it. I used my Pict 34 after I cleaned it and rebuilt it. I’m waiting on a new dizzy to turn up. |
A new aftermarket dizzy can be totally junk!
Many of them make 40 to 45° BTDC when static at 7,5°. For me, a absolute NO GO!
Imo, a good used original or a restored one is the very best choice. |
This is the one that came today. |
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heimlich
VWNOS.com
Joined: November 20, 2016
Posts: 7420
Location: Houston, Texas
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| Posted: Wed May 07, 2025 8:37 am Post subject: Re: Bocar pict 34 3 woes |
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| soggz wrote: |
| Hi. My bocar carb has probably only done around 2000 miles. I rebuilt it a couple of weeks ago, as I replaced my fuel tank which kept blocking the carb with rust from it. I will take the carb off and go through it again. |
The same thing happened to me. Check your fuel filters. Also the idle/pilot jet gets clogged easily as well from rust that bypasses the filter.
If there is nothing wrong with your AJ distributor mechanically it should work fine for your application. I mentioned it earlier: Try running the Bocar without the retard hose attached. Also plug it at the carburetor. Time it as you would an SVDA, 7.5 at idle and 850 or so.
_________________
www.vwnos.com [email protected]
Classic Brands. Classic Quality.
Not all parts are made the same. NOS OE/OEM parts made mainly in West Germany, Early Germany, and Early Brazil are where VW produced the best quality parts and best fitting products.
5% Off your order with coupon code: 5%OFF
Restored Distributors Available (<--Click here) |
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