Whats the best way to set your idle speed?
Using the air/fuel mixture screws?
Or getting a good mixture then using the throttle stop screws?
76camper Fahrvergnugen
884 posts · joined Jan 2005 ·
Setting your idle speed
Chewy Fahrvergnugen
889 posts · joined Jul 2004 ·
Set the idle mixture first then the idle speed with the throttle stop , do both when the engines at operating temperature...
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1303Steve Scirocco Rare
8,650 posts · joined Aug 2002 ·
barenyisbeetle Commited Dubber
63 posts · joined Mar 2005 ·
Firstlly, What shape are your linkages butterflys and vacum/breather hoses carbie n idle solinoids. If any of these are worn leaking. Reduce your odds of a frustrating experience. With a dodgey set up you may strike it lucky but its rare. and unless you know the difference your bound to tinker. if all of this is ok then your ready to start.
76camper Fahrvergnugen
884 posts · joined Jan 2005 ·
We have been doing it just by using the mixture screws.... It seems fine, just wondering whats best. Will give what that site said a go.... What are the disadvantages of just using the idle screws?
barenyisbeetle Commited Dubber
63 posts · joined Mar 2005 ·
When everything is tidy ie not leaking or lose. Turn the idle jet screws one and a halve turns out from closed then use nail polish and varnish them so they dont work there way out. when dry. like tommorow, Set vacum(large screw on left carbie at 3/4 open and small screw 1 1/2 turns open from closed.
Pull off vac advance tube from right hand carbie and lead to large idle solinoid on the left. use best judgement or carb synch and adjust throttle stop screws to set idle at 900 rpm.set mixture screws at the base of each carbie at about 4 turns out from closed,as a starting point.
Reconnect large solonoid and vacum advance tube. Revs will rise by 50 rpm or more.
Now use the mixture screws at the base of the carbies to rich or lean out air fuel mixture refer to carb sync to balance out. Or if you have a musical ear use a peice of 1/2 tube long enough to place one end in your ear and the other over the carbie throat. adjust mixture to balance according to pitch.
Pull off vac advance tube from right hand carbie and lead to large idle solinoid on the left. use best judgement or carb synch and adjust throttle stop screws to set idle at 900 rpm.set mixture screws at the base of each carbie at about 4 turns out from closed,as a starting point.
Reconnect large solonoid and vacum advance tube. Revs will rise by 50 rpm or more.
Now use the mixture screws at the base of the carbies to rich or lean out air fuel mixture refer to carb sync to balance out. Or if you have a musical ear use a peice of 1/2 tube long enough to place one end in your ear and the other over the carbie throat. adjust mixture to balance according to pitch.
General_Failure Use your head, don't abuse it!
1,036 posts · joined Jun 2004 ·
I have a question.
My van was an auto converted to manual. Are the preheat things on the carbs meant to be disconnected or connected? They are not connected on my motor. They haven't been since the conversion.
My van was an auto converted to manual. Are the preheat things on the carbs meant to be disconnected or connected? They are not connected on my motor. They haven't been since the conversion.
If at first you don't succeed. Build, build again.
Vehicle: 1975 Special order delivery walkthrough panel based LCA pop-top camper. Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.
Vehicle: 1975 Special order delivery walkthrough panel based LCA pop-top camper. Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.
76camper Fahrvergnugen
884 posts · joined Jan 2005 ·
It should be on there, I dont think there is any difference between an engine that was connect to an auto trans stock or a manual trans stock. Not having that part will effect your carbs, a guy was talking about his carbs icing up, that is the result of no preheat.... I think i might have the peice your looking for lying around, i will have a look and if i do i will u2u u...
Chewy I will give that a go, sounds easier than wat that site was saying... Just waiting on an indicator stalk so i can take it for a drive to get it upto temp, waste of fuel the car just sitting there at idle for 1/2 hour.... probably not good for it either
Chewy I will give that a go, sounds easier than wat that site was saying... Just waiting on an indicator stalk so i can take it for a drive to get it upto temp, waste of fuel the car just sitting there at idle for 1/2 hour.... probably not good for it either
Andy Andy\'s Adventures
2,820 posts · joined Nov 2002 ·
Oh dear oh dear, what can I say?
Firstly I will assume you have a late T2 kombi with type 4 motor??
I guess to answer your very specific question at the top, just the way VW intended, with the large brass screw in the left hand carbie. Neither of the options you suggest!!
You also ask "What are the disadvantages of just using the idle screws?" I think you mean idle mixture adjustment screw? Well you want to change the engines speed, but you are varying the air fuel ratio (mixture)! Disadvantages are simple, you will harm your motor.
Please buy a BENTLEY workshop manual for your model bus, follow the setup procedure for the carbies to the letter. You will never look back.
Can't say I fully agree with the recommendations of the clubvw tech page, but that's a matter of opinion, following it though will get your carbies setup and working well.
Richard
Firstly I will assume you have a late T2 kombi with type 4 motor??
I guess to answer your very specific question at the top, just the way VW intended, with the large brass screw in the left hand carbie. Neither of the options you suggest!!
You also ask "What are the disadvantages of just using the idle screws?" I think you mean idle mixture adjustment screw? Well you want to change the engines speed, but you are varying the air fuel ratio (mixture)! Disadvantages are simple, you will harm your motor.
Please buy a BENTLEY workshop manual for your model bus, follow the setup procedure for the carbies to the letter. You will never look back.
Can't say I fully agree with the recommendations of the clubvw tech page, but that's a matter of opinion, following it though will get your carbies setup and working well.
Richard
76camper Fahrvergnugen
884 posts · joined Jan 2005 ·
"You also ask "What are the disadvantages of just using the idle screws?" I think you mean idle mixture adjustment screw? Well you want to change the engines speed, but you are varying the air fuel ratio (mixture)! Disadvantages are simple, you will harm your motor."
I have been using these screw to set the idle... the two brass screws ontop of the left carb! The 'idle screws' i was talking about were the throttle stop screws which are part of the throttle mechanism.
"We have been doing it just by using the mixture screws.... It seems fine, just wondering whats best. Will give what that site said a go.... What are the disadvantages of just using the idle screws?"
I have the original owners manual but, i was just trying to find out how most people set the idle on their carbs, just trying to find out if i was doing it right or not, if there was a better way of doing it... still learning...
I have been using these screw to set the idle... the two brass screws ontop of the left carb! The 'idle screws' i was talking about were the throttle stop screws which are part of the throttle mechanism.
"We have been doing it just by using the mixture screws.... It seems fine, just wondering whats best. Will give what that site said a go.... What are the disadvantages of just using the idle screws?"
I have the original owners manual but, i was just trying to find out how most people set the idle on their carbs, just trying to find out if i was doing it right or not, if there was a better way of doing it... still learning...
Andy Andy\'s Adventures
2,820 posts · joined Nov 2002 ·
Hi,
I was not trying to sound too harsh, just there's a wealth of miss information out there.
It makes no difference if you set the idle speed with the idle mixture screw or the throotle stop screws, both will affect mixture, and need to be adjusted together.
Stock type 4 dual carb setups are not that hard to tune, but for some reason most people say it's too hard and either give up or try to eliminate the central idle system.
I keep the central idle system operational on my bus's and can then use the large brass screw on top of the LH carb to set idle speed, just as the factory intended. You can eliminate it if you wish and set the the carbs up like a "normal" dual carb setup, but balancing becomes much more critical for smooth reliable running.
So, you can use the link above if you prefer to eliminate the central idle system (and you don't need to tamper with the large solenoid to do this as they suggest) Or if you prefer to setup using the central idle system I can send you links to pages that detail this proceedure.
Richard :thumb
I was not trying to sound too harsh, just there's a wealth of miss information out there.
It makes no difference if you set the idle speed with the idle mixture screw or the throotle stop screws, both will affect mixture, and need to be adjusted together.
Stock type 4 dual carb setups are not that hard to tune, but for some reason most people say it's too hard and either give up or try to eliminate the central idle system.
I keep the central idle system operational on my bus's and can then use the large brass screw on top of the LH carb to set idle speed, just as the factory intended. You can eliminate it if you wish and set the the carbs up like a "normal" dual carb setup, but balancing becomes much more critical for smooth reliable running.
So, you can use the link above if you prefer to eliminate the central idle system (and you don't need to tamper with the large solenoid to do this as they suggest) Or if you prefer to setup using the central idle system I can send you links to pages that detail this proceedure.
Richard :thumb
General_Failure Use your head, don't abuse it!
1,036 posts · joined Jun 2004 ·
Some links to sites on correctly adjusting the central idle system would be great.
The preheat things I'm referring to are designed to change the output of the throttle pump depending on temperature. It uses heating to alter a valve of some sort. The manual's in the other room. Don't feel like digging it up right now.
It is true, the auto and manual motors are mostly the same. The main difference really is the carbs. I think there may be a few other alterations, but they aren't as important.
The preheat things I'm referring to are designed to change the output of the throttle pump depending on temperature. It uses heating to alter a valve of some sort. The manual's in the other room. Don't feel like digging it up right now.
It is true, the auto and manual motors are mostly the same. The main difference really is the carbs. I think there may be a few other alterations, but they aren't as important.
If at first you don't succeed. Build, build again.
Vehicle: 1975 Special order delivery walkthrough panel based LCA pop-top camper. Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.
Vehicle: 1975 Special order delivery walkthrough panel based LCA pop-top camper. Motor: Nippon 1.8L Single port Wasserboxer, Transmission: 3 rib 002.
76camper Fahrvergnugen
884 posts · joined Jan 2005 ·
So setting the idle using the brass screws on LHS carbie is the best way to set the idle and just unscrew the idle stop screws so they dont effect the idle?
Please send some links, am just curious if im doin it right!
Please send some links, am just curious if im doin it right!
1303Steve Scirocco Rare
8,650 posts · joined Aug 2002 ·
Hi
The left hand carb conatians the central idle curcuit. Like the article said get the idle working evenly on each carb, just like setting up any dual carb, only have a lower idle speed, then adjust the idle speed & mixture with th screws in the top of the left hand carb.
Steve
The left hand carb conatians the central idle curcuit. Like the article said get the idle working evenly on each carb, just like setting up any dual carb, only have a lower idle speed, then adjust the idle speed & mixture with th screws in the top of the left hand carb.
Steve
Andy Andy\'s Adventures
2,820 posts · joined Nov 2002 ·
Ok, first things first, you need to ask why you are you fiddling with the carbie?
If you had a well tuned running kombi and things have slowly changed, chances are it’s not the carbs. Similar can be said if it suddenly turns sick. From my experience you only need to adjust the carbs if a PO (previous owner) has been in there or you got the bus in a poor state and you need a base to start from.
If idle speed has slowly changed, it’s usually the points gap or timing causing this!
Lets assume your bus has either always run crook, or you fear a PO has been in there fiddling (or now you’ve started to adjust things and no longer know where your at). The very first thing you should do is a full service; this includes checking valves, points, timing, dwell, plugs, distributor function etc. All are needed correct before proceeding. It’s also a good idea to check the fuel pump and replace the fuel filter. The last step before tuning is to make sure the bus is warmed up, take it for a short spin of 5-10km to do this.
Now you’re ready to tune the carbs, and set the idle speed. I’ll leave you to read the links below on how to do this, most are re-wording what’s in the Bentley manual already but may be easier to understand.
Some points I will stress are to make sure the chokes are fully off before tuning, set the throttle stops as per the manual, make sure throttle linkages are balanced, and finally do it SAFELY, you will be playing with a hot running motor!!
Oh, just so you know, on the later dual PDSIT setups there quite a number of things made to vary between start up and running temp. Chokes, a thermostatically controlled jet to add fuel into the central idle, a thermostat to vary accelerator pump volume, thermostat for hot air inlet on air box, AND as you mention an additional two thermostatically controlled jets that put fuel directly into the manifold for automatic kombi’s. That’s all in addition to the 3 solenoids in the idle circuits.
There is a lot to look for keeping an old VW on the road, but broken down they are all simple steps most people should be able to do themselves.
http://www.type2.com/library/fuel/dualsol.htm
http://www.type2.com/library/fuel/34pdsit.htm
http://www.ratwell.com/technical/DualCarbs.html
http://www.type2.com/library/library.htm
:blah
If you had a well tuned running kombi and things have slowly changed, chances are it’s not the carbs. Similar can be said if it suddenly turns sick. From my experience you only need to adjust the carbs if a PO (previous owner) has been in there or you got the bus in a poor state and you need a base to start from.
If idle speed has slowly changed, it’s usually the points gap or timing causing this!
Lets assume your bus has either always run crook, or you fear a PO has been in there fiddling (or now you’ve started to adjust things and no longer know where your at). The very first thing you should do is a full service; this includes checking valves, points, timing, dwell, plugs, distributor function etc. All are needed correct before proceeding. It’s also a good idea to check the fuel pump and replace the fuel filter. The last step before tuning is to make sure the bus is warmed up, take it for a short spin of 5-10km to do this.
Now you’re ready to tune the carbs, and set the idle speed. I’ll leave you to read the links below on how to do this, most are re-wording what’s in the Bentley manual already but may be easier to understand.
Some points I will stress are to make sure the chokes are fully off before tuning, set the throttle stops as per the manual, make sure throttle linkages are balanced, and finally do it SAFELY, you will be playing with a hot running motor!!
Oh, just so you know, on the later dual PDSIT setups there quite a number of things made to vary between start up and running temp. Chokes, a thermostatically controlled jet to add fuel into the central idle, a thermostat to vary accelerator pump volume, thermostat for hot air inlet on air box, AND as you mention an additional two thermostatically controlled jets that put fuel directly into the manifold for automatic kombi’s. That’s all in addition to the 3 solenoids in the idle circuits.
There is a lot to look for keeping an old VW on the road, but broken down they are all simple steps most people should be able to do themselves.
http://www.type2.com/library/fuel/dualsol.htm
http://www.type2.com/library/fuel/34pdsit.htm
http://www.ratwell.com/technical/DualCarbs.html
http://www.type2.com/library/library.htm
:blah
76camper Fahrvergnugen
884 posts · joined Jan 2005 ·
Thanx, some very helpful info... We just rebuilt the motor and are still tuning it to get the most out of the engine and ensure the longevity of the rebuild.
The valves, timing and all that are sweet... the engine is running well but getting the carbs tuned right effects the motor ALOT. I will give the idle a go when i get a new indicator stalk (so i can drive it and get it warm). Thanx again
The valves, timing and all that are sweet... the engine is running well but getting the carbs tuned right effects the motor ALOT. I will give the idle a go when i get a new indicator stalk (so i can drive it and get it warm). Thanx again
Andy Andy\'s Adventures
2,820 posts · joined Nov 2002 ·
If it's a re-built motor, did you also re-build the carbs? PDSIT's tend to get a fair bit of wear on the throttle shaft which can cause leaks, and a new gasket kit will not go astray. Once you get it on the road keep an eye on plug colour, valve clearences and temps, their also good indicators if everything is OK.