| Author |
Message |
AWatry
Samba Member
Joined: January 07, 2011
Posts: 9
Location: Berkeley, CA
|
 Posted: Tue Jan 18, 2011 1:14 pm Post subject: |
 |
|
Thanks; will try.
I also realize maybe it needs the vacuum retard (coming off the carb to the other side of the dist vacuum chamber)? That is disconnected and plugged too.
The AE series engine originally called for 5* or so ATDC timing, later changed; would too much static advance (6* BTDC) cause stumbling off idle as the air/fuel mixture in the carb tries to "catch up" with the spark advance?
Andrew |
|
| Back to top |
|
 |
borninabus
Samba R&D Dept.
Joined: May 18, 2006
Posts: 4538
Location: Arizona Highways
|
| Posted: Tue Jan 18, 2011 3:52 pm Post subject: |
|
|
| AWatry wrote: |
| The AE series engine originally called for 5* or so ATDC timing, later changed; would too much static advance (6* BTDC) cause stumbling off idle as the air/fuel mixture in the carb tries to "catch up" with the spark advance? |
no.
timing specs are based on the dist being used. not the engine.
_________________
88 Van WBX, A/T - 13 JSW TDI 6M/T - 2012 Touareg TDI Sport |
|
| Back to top |
|
|
AWatry
Samba Member
Joined: January 07, 2011
Posts: 9
Location: Berkeley, CA
|
| Posted: Wed Jan 19, 2011 2:37 pm Post subject: |
|
|
Right, but all AE series engines use the 34 PICT, right? Which has to have the right dist combo with it. AirHeadParts specifically calls out that this engine/dist combo needs a vacuum/mechanical advance dist, and that 009 dist, for instance, won't work well on a stock engine.
Andrew |
|
| Back to top |
|
|
SGKent 
Samba Member
Joined: October 30, 2007
Posts: 41031
Location: Citrus Heights CA (Near Sacramento)
|
| Posted: Wed Jan 19, 2011 3:47 pm Post subject: |
|
|
| AWatry wrote: |
Right, but all AE series engines use the 34 PICT, right? Which has to have the right dist combo with it. AirHeadParts specifically calls out that this engine/dist combo needs a vacuum/mechanical advance dist, and that 009 dist, for instance, won't work well on a stock engine.
Andrew |
I agree that the best solution is the factory one however I ran a 34 pict 3 with an 009 without problems for a couple of years on a 1971 Dp doghouse AE.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
|
| Back to top |
|
|
sunbugone
Samba Member
Joined: January 12, 2005
Posts: 85
Location: Houston, TX
|
| Posted: Fri Jan 21, 2011 11:23 am Post subject: |
|
|
I have a rebuilt/rebushed 34 that has a high idle (bypass screw all the way in) It runs crisp after jetting, volume screw sets as it should but once it is at its cleanest idle I can't bring it down. SVDA distributor set at 7.5 btdc. No vacuum leaks. It idled fine with the h30/31 Just ran like crap overall. I may have an autostick carb but I need to check the base# Choke cam screw is set correctly also and throttle cable is disconnected as well. Thoughts??
_________________
1974 Sunbug
1974 Sunbug Convertible
1970 Westfalia |
|
| Back to top |
|
|
busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51145
Location: Surrey B.C. Canada, but thinking of Ukraine
|
| Posted: Fri Jan 21, 2011 11:36 am Post subject: |
|
|
What size is the hole in the throttle plate? Shure the fast idle cam isn't holding it open?
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
| Back to top |
|
|
sunbugone
Samba Member
Joined: January 12, 2005
Posts: 85
Location: Houston, TX
|
| Posted: Fri Jan 21, 2011 12:01 pm Post subject: |
|
|
I will have to check the hole in the throttle plate this evening. No, the cam is not holding it open, the throttle plate is completely shut. I have set hundreds of these carbs and never run into this problem...weird. I thought all factory solex carbs had a small hole drilled in the throttle plate but I have never looked that deep into it. This thread is an interesting read
_________________
1974 Sunbug
1974 Sunbug Convertible
1970 Westfalia |
|
| Back to top |
|
|
sunbugone
Samba Member
Joined: January 12, 2005
Posts: 85
Location: Houston, TX
|
| Posted: Sat Jan 22, 2011 12:33 pm Post subject: |
|
|
There is one hole in this throttle plate. If I had to take I guess I would say its about 3.5-4mm in diameter
_________________
1974 Sunbug
1974 Sunbug Convertible
1970 Westfalia |
|
| Back to top |
|
|
busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51145
Location: Surrey B.C. Canada, but thinking of Ukraine
|
| Posted: Sat Jan 22, 2011 1:02 pm Post subject: |
|
|
All 34PICT3's have a hole but some are larger than others, if the carb is intended for use with a DVDA distributor the hole is bigger (retarded idle timing = more flow), you may have to decrease the size of the hole if you are sure you don't have any vacuum leaks.
Consult this handy carb base number chart. to see what you have.
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
| Back to top |
|
|
sunbugone
Samba Member
Joined: January 12, 2005
Posts: 85
Location: Houston, TX
|
| Posted: Sat Jan 22, 2011 1:57 pm Post subject: |
|
|
377_1 is the base number. So I have a carb that should run 5 after on the timing. I just compared it to a 74' I have and the hole is bigger. Sounds like I found my problem
_________________
1974 Sunbug
1974 Sunbug Convertible
1970 Westfalia |
|
| Back to top |
|
|
busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51145
Location: Surrey B.C. Canada, but thinking of Ukraine
|
| Posted: Sat Jan 22, 2011 2:59 pm Post subject: |
|
|
| sunbugone wrote: |
| So I have a carb that should run 5 after on the timing. |
Yes, if you have the correct distributor, a SVDA doesn't have the retard function so 7.5 BTDC is likely the best spot for it (28 BTDC @3500 RPM with the hose off is the ideal spot), it's also a good idea to determine exactly what pulley you have as marks vary considerably year to year.
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
| Back to top |
|
|
Nweuros
Samba Member
Joined: January 04, 2011
Posts: 25
Location: Puyallup
|
| Posted: Mon Jan 24, 2011 8:09 pm Post subject: |
|
|
| this helped me tremendously. Bus is running great now! Thanks guys! |
|
| Back to top |
|
|
jonblack
Samba Member
Joined: September 23, 2010
Posts: 123
Location: Louisiana
|
| Posted: Wed Mar 09, 2011 6:17 pm Post subject: |
|
|
| Johnf3 wrote: |
| busdaddy wrote: |
| Not on a 34PICT3, CW=leaner, CCW=richer. |
In my initial search, I turned up vw-resource.com, and that is where I got my bad information on how the volume control screw works. |
I was doing some research on how to properly set a 34PICT-3 carb and I came across the same page. I also found some conflicting information.
| Quote: |
| #7 Next set the volume of gas available at idle speeds. This is done using the Volume Control Screw. Please note that the Volume Control Screw controls the AIR volume, not the fuel volume. Screwing it in reduces the air and makes the fuel/air mixture richer. And of course turning the Volume Control Screw out increases the concentration of air and makes the mixture leaner. |
| Quote: |
| #13 Then turn the Volume Control screw back IN (clockwise) very slowly until the engine speed drops by about 20-30 rpm (slightly leaner). If you don't have a tachometer, listen until you can just hear the engine speed start to drop, maybe as little as 1/8th turn on the Volume Screw. |
Unless I am mis-reading his instruction they appear to be conflicting. I will keep reading this thread and hopefully figure out the right way. I also have a Bentley, but I like reading on the internet, too.
I don't have an idle problem other than I think I am too rich. Need to pull the plugs to confirm.
jonblack
_________________
1970 VW Campmobile - owned since July 2010
1600 cc dual port engine
34PICT-3 Carburetor
Bosch 205T - has leaky vacuum advance unit - do you have a reasonably priced one?
Points and condensor
Here to learn how to repair and maintain my bus |
|
| Back to top |
|
|
jonblack
Samba Member
Joined: September 23, 2010
Posts: 123
Location: Louisiana
|
| Posted: Wed Mar 09, 2011 6:53 pm Post subject: |
|
|
| busdaddy wrote: |
| it's also a good idea to determine exactly what pulley you have as marks vary considerably year to year. |
Thanks for mentioning this. I did a search and found the pulley ID thread. I was mistaken on how my pulley marks made out. I think I have a better grasp on it now.
Thanks again
jonblack
_________________
1970 VW Campmobile - owned since July 2010
1600 cc dual port engine
34PICT-3 Carburetor
Bosch 205T - has leaky vacuum advance unit - do you have a reasonably priced one?
Points and condensor
Here to learn how to repair and maintain my bus |
|
| Back to top |
|
|
busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51145
Location: Surrey B.C. Canada, but thinking of Ukraine
|
| Posted: Wed Mar 09, 2011 9:11 pm Post subject: |
|
|
There's lots of confusion about the names of those 2 screws, what Bentley calls the volume screw is commonly called the mixture screw on most other vehicles. Bottom line is the bigger screw controls the amount of air/fuel mixture allowed to bypass the throttle plate. Opening and closing the big screw does not effect the mixture at all, only the volume of mixed air/fuel admitted (confused yet?), the small screw determines whether that mixture is rich or lean.
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
| Back to top |
|
|
Ghia72
Samba Member
Joined: February 21, 2011
Posts: 24
Location: Dillon, MT
|
| Posted: Wed Mar 23, 2011 3:22 pm Post subject: |
|
|
so, i tried the idle screw out, in, across the street, buried, no matter where i put the thing my ghia wont idle. both the big screw and the little screws are screwed about 2 and half times out. I've basicly read this entire string looking for an answer and i cant find it. any other ides? My carb is the OG pict 34.
Thanks |
|
| Back to top |
|
|
busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51145
Location: Surrey B.C. Canada, but thinking of Ukraine
|
| Posted: Wed Mar 23, 2011 4:17 pm Post subject: |
|
|
If the solenoid works the next step would be check the idle jets for blockages, after that it's onto the passages between the jets and the screws.
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
| Back to top |
|
|
Ghia72
Samba Member
Joined: February 21, 2011
Posts: 24
Location: Dillon, MT
|
| Posted: Wed Mar 23, 2011 8:54 pm Post subject: |
|
|
| the solenoid to the starter???????????????? |
|
| Back to top |
|
|
busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51145
Location: Surrey B.C. Canada, but thinking of Ukraine
|
| Posted: Wed Mar 23, 2011 9:56 pm Post subject: |
|
|
No, the idle cutoff solenoid, the metal cylinder sticking out the LH side just above the throttle shaft with the spade terminal on the plastic end. If it doesn't click when it gets 12V from #15 on the coil the carb won't idle.
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
| Back to top |
|
|
Dauz
Samba Member
Joined: January 05, 2010
Posts: 1790
|
| Posted: Wed Apr 20, 2011 8:52 pm Post subject: |
|
|
I've searched these forums and basically utilized the same fix most everyone else has.
My spare motor:
1600DP STOCK
34 PICT 3 with 034 SVDA
Starts and idles until it warms up and then dies when the choke is fully closed. The fix was to back off the pilot jet slightly after cleaning it and blowing it with compressed air. Dab of thread lock where the sweet spot is and it's running like a CHAMP! |
|
| Back to top |
|
|
|
