timing / tuning help

[lard]

I've been slowly getting my bus sorting out and now have all the components ready,

It's a 1600 TP and I've fitted a new carb, replaced alternator and since adjusted valves all round, checked & adjusted spark plug carbs, a compression check shows all around 125 -130

The only thing I haven't worked out is the timing and think this is causing the stuttering I'm having under acceleration

Went into a local garage when I first got it (haven't got a strobe yet!) and the guy reckened it wasn't far out and was set to 7 degress...( :?: )

My brother was down this weekend and putting his strobe on showed that the timing notch was showing behind the crankcase split (to the left) ...the pulley also only has one notch on it and a painted line to the right of this - checked timing with gun and the notch and line are both quite far to the left of the crankcase split..?

(forgive my vagueness...timing isn't my strong point!)

thought we'd check Muir/Benson to see what the timing should be on my engine and this is where the confusion came in - the engine number (stamped under the alternator pedestal) is 5545 AD 34166 - I can't see this in any of the tables?

It's running a vac dizzy with the number stamped on it starting "0231" - again, can't find in the manual's to see what the timing should be?

Any one offer any help with this? It's a 1971 bus but obviously not the origanol engine (as doesn't have the 71 manifold e.t.c.) and at a loss as to what the timing should be

Setup the new carb to idle at 850-900 and it's idling rough at the moment (not a steady idle) - with hesitation/missing under all acceleration unless at high rev's in the gears

It had this hesitation before I changed the carb (but now doesn't leak fuel...which is nice!)

shot of dizzy if that helps:

and engine (I've since changed the air cleaner to correct year one)

Just wondering what the timing should be set to and then I can have another go at setting the carb - at the moment I'm thinking that no amount of carb tweaking will be worthwhile until the timing is known to be correct?

any help identifying the engine and dizzy combo would be appreciated!

thanks,

larry

 

[lard]

Shot of the engine if it helps:

 

[oneday!]

Hi Larry

I have a 1971 engine code ad, the setting is 7.5 im running 009 dizzy how many notches do you have on your pulley?
i dont think that your problem is timing sounds more like air leak or carb not tuned correctly my pennys anyway
keep us posted

 

[froggy]

The engine needs timing to what ever dizzy is fitted, the number on the dizzy that counts are the last 3 numbers (i.e. 009, 205, 010 etc) think there is a full listings of dizzy's on the old volks home website which will also give you the recommended timing settings and whether its set with vac on or off and blocked

 

[lard]

Hi Larry

I have a 1971 engine code ad, the setting is 7.5 im running 009 dizzy how many notches do you have on your pulley?
i dont think that your problem is timing sounds more like air leak or carb not tuned correctly my pennys anyway
keep us posted

Hi - it's got just the one notch on the pulley

currently looking through google images to spot which dizzy I have

Thanks for the clarification froggy - if it's the last 3 digits then that may explain my confusion!

Cheers,

Larry

 

[lard]

The engine needs timing to what ever dizzy is fitted, the number on the dizzy that counts are the last 3 numbers (i.e. 009, 205, 010 etc) think there is a full listings of dizzy's on the old volks home website which will also give you the recommended timing settings and whether its set with vac on or off and blocked

spot on - got this from Old Volks:

Distributor: VW 043-905-205 ZB, Bosch 0231 170 034 (Mexico)
Can Use: VW 113-905-205AL, Bosch 0231 146 101, VW 043 905 205, 0231 170 034 (German)
Notes: This is the Mexican manufactured version of the original 043 905 205 Distributor, originally used on 1974 Federal Manual Transmission Beetles. This was used on Mexican production Beetles early on before they switched to Electronic Ignition (year periods are unknown, but I believe it was sometime in the 80s). This distributor comes with a Single Vacuum Can is essentially a carbon copy of the original German made model. It uses all of the same components of the original German Distributor except the Condensor as noted below. Timing specs are the same as well and have not changed.
This is THE Distributor to use on your stock engine w/Solex 30PICT-3, H30/31PICT Series or 34PICT Series carbureted 1600 Beetle thru 1974 (75-79 w/Carb) & Type 2 1600 thru 1971. It is NOT recommended for use with the 30PICT-1 or 30PICT-2 because the vacuum signal is incorrect for the vacuum assist to work properly. This Distributor is essentially a "009" with a Vacuum Advance Assist to help prevent hesitation in all of those Stop-n-Go situations in city traffic. The Mechanical Advance takes over out on the highway to provide the most excellent Advance Curve in all sorts of engine loads. If you're running an original Dual-Vacuum Distributor on your Beetle 71-74/Type 2 1971 application(s), you will need to cap off the "Retard" Vacuum Port located on the rear of the Carburetor. Available new from a number of VW Parts Suppliers.
This distributor is similar to but should not to be confused with the "Bruck Germany" Distributor being sold by a number of outfits. In actuality, this is a Chinese knock-off of the Bosch Mexican "034" and the reliability of this distributor has not yet proven itself IMHO. Let the buyer and user beware!
Points: 01 011
Condensor: 02 054 (German model used 02 074)
Rotor: 04 033
Dust Cover: 039-905-241, Bosch 1230 500 139 > 1230 500 147
Cap: 03 010
Distributor Cap Clip: 034-905-265, Bosch 1231 251 033
Parts Kit (Shims, Washers & Hardware): 059-998-211, Bosch 1237 010 007
Coil: 00 015 (Blue Coil: 00 012)
Vacuum Can: 07 059
Ignition Wires: 09 001
Spark Plug: W8AC
Timing Set At:: 7.5deg BTDC @ 800-950rpm w/strobe and w/single vacuum hose disconnected and plugged
Advance/Retard Range: Vacuum: 8-12deg Adv; Centrifugal: 8deg @ 1300rpm, 10deg @ 1600rpm, 15deg @ 2500rpm, 20deg @ 3000rpm, 21deg @ 3500 to 4000rpm
Note: The Advance ranges shown are courtesy of Richard Atwell who performed a test of this distributor's capabilities on a Sun Distributor testing machine. You can view the appropriate advance graph images at the following links :
http://www.ratwell.com/technical/FAQ...yCurvesVac.gif" onclick="window.open(this.href);return false;
http://www.ratwell.com/technical/FAQ...izzyCurves.gif" onclick="window.open(this.href);return false;

Checked and the numbers on the dizzy are 0231 170 034 so it's 7.5 BTDC

confused the hell out of me as Muirs/Bently's don't list my engine or this dizzy and timing for my year is listed as 5deg - as it's been set to this already I can turn my attention to tuning the carb

Thanks,

Larry

 

[lard]

o.k. running out of idea's now

Found TDC using the pencil method, set all valves to 0.06
TDC is marked by a flat spot on the pulley and notch matches up to 7.5 BTDC - have attempted to advance/retard timing slightly to get round die on idling issue
Setup carb (2/12 turns out & set to idle at between 850 - 900 - idle is erratic though)

I've timed and re-timed and also setup the carb multiple times but I the van still dies on idle when I put the clutch in after driving it - it idles fine on the driveway but as soon as I drive it out and go 100 yds to a junction, put in clutch and engine dies :? - also hesitant on acceleration still

I'm slowly running out of things to check!

Things left that I can think of:

Fuel pump filter (haven't checked it but could it cause this issue?)
The adjustment for fuel volume on the right side of the carb, could it be that under load the float tank is emptying and not getting refilled quick enough?

erm...that's all I can think of at the moment

Any other suggestions on where to look then please let me know!

Thanks,

Larry

 

[Graham L]

Larry

Sorry to see you are still having problems, have you checked whether you have an air leak somewhere on the intake side, gasket on the carb or on the TP manifold. If its pulling air in it could cause the problem.

Don't think it fuel related but have you tried taking the fuel line off the fuel pump to the carb and checking your are getting constant flow whilst the engine is being cranked, doubt its that as you say it runs but won't idle after a run, but you'll be able to check the flow.

Not sure what else to suggest but I'm sure others will be along with some advice soon,

 

[lard]

Larry

Sorry to see you are still having problems, have you checked whether you have an air leak somewhere on the intake side, gasket on the carb or on the TP manifold. If its pulling air in it could cause the problem.

Don't think it fuel related but have you tried taking the fuel line off the fuel pump to the carb and checking your are getting constant flow whilst the engine is being cranked, doubt its that as you say it runs but won't idle after a run, but you'll be able to check the flow.

Not sure what else to suggest but I'm sure others will be along with some advice soon,

Hi Graham,

It's not so bad ironing out the last of the jobs - if it didn't need any tinkering I couldn't hide in the garage and that's half the fun :mrgreen:

Cheers for the advise though - it looks like I've got a cracked plastic flange between the base of the pump and the engine block so will doubtless replace the lot at some point,

Have made some progress though which is nice:

Firstly though I'm going to have to put my hands up to doing something daft

So after installing the new carb to resolve the fuel seepage issues this is where the lack of idle after load came in....what I completely forgot about was that I also cleaned up and installed an OG 1971 air cleaner on the bus that came a while ago whilst waiting for the new carb to be delivered.....when I say cleaned up I basically blew out all the crap in the top section and cleaned up all the old dust and oil out the bottom (my excuse is my 5 year old was hassling to help on "camper jobs" so I was distracted!)

So - bearing this in mind, stuck the OG bocar carb and 1972 air cleaner on it and.....it idles fine - so my theory is that some f****ing idiot pulled through years worth of god knows what into the new carb from the (know known to be rusty :roll: ) metal elements in the air filter (that'll be me then!)

At least the comfort is that if this is likely to block the idle circuit or where ever and cause this type of problem then I can put my finger on the cause and move on, just need some pointers on where to check in the carb for some hiding debris to get my new carb back on line?

 

[lard]

Last query for those in the know is about the timing,

So it went to a local VW independent and they reckoned it was spot on 7.5 BTDC

My pully (had a good search on here, VZI & thesamba!) only has 1 factory mark, a notch - a painted white line and some home made hacksaw jobs,

So - got a vacuum advance gun and set about checking how it was set, it was timed to the existing white paint line...which kinda makes sense - which meant the notch must have been TDC.......but looking in the references 7.5 BTDC engines didn't have a notch for TDC just one for timing....

That got me thinking so decided to find TDC myself with a pencil in cylinder 1 and to my surpise..it lined up with a barely noticable "dent" in the top edge of the pully suspiciously far away from the notch to indicate this was a timing notch :shock:

So - timed the engine at 850 ish to the notch and then wound up the dial to 7.5 and it showed the dent in line with the case :mrgreen: - which means the van had been timed too advanced? Not sure who put the white line on the pulley so could have been like than from PO and the garage just assumed it was correct? Or they measured 7.5 after finding TDC and painted the line (and came to completely different calculations that me) or my timing gun is knacker, but I just bought it and it's still clean and shiny, tested it static to the notch and via the dial to TDC :|

Anyway - after waffling (I've got flu and can't talk so this may explain the long post!) - I've been playing with the advance and have a couple of questions,

Timing it to 7.5 is probably the "roughest" sounding it can be (or alternatively, the first point at which it doesn't stall from being too retarded) - advancing it even slightly to 10 makes it a whole lot stabler but I'm a bit (green!) and worried to leave it on this setting after stories of knocking e.t.c. and damage to valves

It's a single vac unit and advances as the revs increase e.t.c. - but not knowing what "pinking" sounds like I can't be happy knowing if it is or isn't set correctly? Is there a way to test this? Such as turn it clockwise until it makes "xxx" sound and then drop it back (which is what seems to improve the steadyness of the idle) and check timing then to see the region it's in?

From experience...do buses each have their own habits and some like to be advanced/retarded slightly or is it a hard and fast rule to the nth degree?

Retarding it further than 7.5 causes it to almost lose idle - going to 7.5 it's a bit lumpy with the occasional stumble - past this to 10 and it just picks up and sounds smoother (there is a high pitched ticking noise that comes from the manifold - is this pinking? ) is too much advance on the timing the direction in which engine death occurs or is it preferable to too retarded?)

appreciate the advise!

Thanks,

Larry

 

[dubdubz]

shot of the pulley [showing marks] may help....

so are you saying when it's set to 7.5btdc , the new mark it isn't sounding healthy?

where in Cambs are you ? as I have a few spare dizzys that you could try in case yours is giving you grief unknowingly - I'm in Peterbrough so shouldn't be too far away?

You can always borrow the one of my working engine too if you wanted - drop me a pm and we'll sort something out....

It could be mixture now but swapping a known to be working dizzy will help imho - obviously I could be wrong!! :lol:

 

[lard]

shot of the pulley [showing marks] may help....

so are you saying when it's set to 7.5btdc , the new mark it isn't sounding healthy?

where in Cambs are you ? as I have a few spare dizzys that you could try in case yours is giving you grief unknowingly - I'm in Peterbrough so shouldn't be too far away?

You can always borrow the one of my working engine too if you wanted - drop me a pm and we'll sort something out....

It could be mixture now but swapping a known to be working dizzy will help imho - obviously I could be wrong!! :lol:

Hey thanks for the offer - that's really appreciated 8) - I'm just north of the City - regards the marks I'll get some shots up, going to double check TDC tomorrow

It sounds healthy enough (as in it doesn't die or hunt too much) timed to what I believe (and the OG notch indicates) is 7.5 BTDC

But not knowing what air coolled engines are supposed to sound like has me doubting, as advancing the timing to 10 seems to improve the idle from a steadyness point of view but I'm assuming this isn't a good thing

As you say though - using a known good dizzy is sound advise as it eliminates that area entirely - I'll get the pully shots up and may even attempt a youtube video just to confirm if the idle seems o.k. - it may even be me thinking too much, only ever worked on brit classics before so it's all new ground to me!

EDIT: Just read up on ignition timing:

Knock occurs on too much advance
Too much retard reduces performance and increases fuel consumption

So in answer to my own question, I think too retarded is better than too advanced!

I'll get those shots up!

 

[Tofufi]

Set it at 7.5 deg BTDC, and then you should adjust the carb afterwards.

The dimple on the edge of the pulley closest to you should be TDC. If it is the original 1971 pulley it will have a notch to the left of this... ignore it, and time to 7.5 deg BTDC (on the pulley the timing mark for this should be to the right of the TDC mark)

Then follow this for a base setting on the carb.

Finally, sort out the air filter you've got fitted in that photo - it is missing the warm air feed and flap device. This could be the cause of the stalling.

Always set timing before setting the fuel/air mixture

 

[matt-me]

Larry, i know where you're coming from here; i asked pretty much the same questions recently. I know i have a re-con engine so i didn't, and don't, know what the correct timing marks are for the engine. The advice is was given was to set it to what sounded and felt right, which is what i had been doing and have still done. In my case it is 10 BTDC. Runs very well after warming up and have done a few miles in it. When i set it at 7.5 or other settings the same happended to me as you're experiencing. I am not a mechanic, all i can do is pass on my experience. Interestingly, when my mechanic did time it, he seemed to be doing it as much by ear and smoothness (lack of flat spots), although he did set it at higher revs with the proper kit, he turned to me and asked sound allright to you? He is a specialist VW man who i do trust.

Slight differences, if it makes a difference, is i have twin ICT's.

Al

 

[lard]

Larry, i know where you're coming from here; i asked pretty much the same questions recently. I know i have a re-con engine so i didn't, and don't, know what the correct timing marks are for the engine. The advice is was given was to set it to what sounded and felt right, which is what i had been doing and have still done. In my case it is 10 BTDC. Runs very well after warming up and have done a few miles in it. When i set it at 7.5 or other settings the same happended to me as you're experiencing. I am not a mechanic, all i can do is pass on my experience. Interestingly, when my mechanic did time it, he seemed to be doing it as much by ear and smoothness (lack of flat spots), although he did set it at higher revs with the proper kit, he turned to me and asked sound allright to you? He is a specialist VW man who i do trust.

Slight differences, if it makes a difference, is i have twin ICT's.

Al

cheers for the advise!

went and checked TDC was on the dimple again to be doubly sure and set about timing it - funnily enough the best timing I get is 10 BTDC, took it for a test run (carb was out but close enough to idle and run) and it pulled cleanly from low revs in 1,2 & 3 without the stutter I was getting at 7.5 BTDC :? - and interestingly the only white painted mark on the pully is bang on 10 BTDC

So looks like PO had it at 10 BTDC - local garage put it to 7.5 as did I and it didn't run well, back to 10 BTDC and fingers crossed it is better now, going to re-setup the carb tomorrow and take it for a 40/50 mile run and see how it goes!

Interesting that we both have the AD engine and 10 BTDC seems to be the sweet spot, yet the mexi dizzy (205 replica) says 7.5 :?:

 

[dubdubz]

what's the max advance? if it runs ok at 10 then fine BUT make sure the max advance is around 30 - or is it 28??