Okay so my old 1600 TP used to pink under load when you pushed the accelerator hard down (ie used the Accelerator pump) when I had a Weber carb of some description on there (I can't figure out which model it is).

So I swapped the carb over, after checking everything else, to the 34PICT 3 and therfore changed the 009 dizzy to my old 1500 one that I had lying around.

Only now it seems worse, ie it pinks under less load!! But push the accelerator to the floor and it goes well.

Is the 1500 dizzy a SVDA dizzy?

What else should I check to sort out this problem. I've looked at points gap, timing, Valve clearances and the carb adjustments - which are pretty limited really.

I've thought of going back to the Weber but it's got a much smaller venturi and I'd need to track down another gasket for it as the last one is stuffed, leaking gas everywhere.

Cheers
Jeremy

Several things will cause ping(k)ing

timing too advanced
too high a compression
too lean of a mixture
air leaks
too low octane in petrol (relates to CR)

you need to eliminate them one by one.

Are you sure your timing is right?
Do you know for sure what the compression ratio is?
Do you know what jets are in your carbs?

The distributor which came with 1500s was an SVSA (single vacuum single advance). Usually a VW 113 905 205M or 205T (Bosch 0231 137 021 or 036)

They will work with the 34PICT/3 carby but are not ideal, since this carby has a different vacuum signal to the 30PICT/2 carby the 1500s used. With the 34 PICT/ this distributor may be pulling in extra advance too soon .

First check your timing - should be 7.5% BTDC for the SVSA distributor, and if you blip the throttle, you should see up to about 40 degrees total advance (make a mark 62mm around the pulley rim to the right of TDC).

A better vacuum distributor for the 34PICT/3 carby is the 71+ SVDA distributor - VW 043 905 205.


If you want to try the 009 again, use 28-32 degrees at 3000+rpm. You can NOT set these up static to 7.5BTDC and expect it to be right at the max advance point - they vary (cheap build).


So you set them at 3000+ rpm and THEN see where the idle advance falls if you want to, then you can use THAT static setting on THAT 009 next time if you prefer to set it that way (it will probably be between 5 and 10BTDC).

I presume that you are certain of the pulley marks you have - there are at least 4 common pulley types with different marks.

If you KNOW where TDC is on that pulley - 28 degrees is 43.5mm to the right around the rim, and 32 degrees is 49.5mm to the right of TDC.

Always use as much of the 28-32 as the engine can take without pinging, but don't go outside that range. If it still pings at 28 degrees, use a higher octane fuel, don't use less than 28 degrees advance, or the engine will run hotter at higher rpm than it needs to, which will make any pinging problem worse! If you use more than 32 degrees, it may start pinging when you floor it at medium speeds.

Jetting for the 34PICT/3 and vacuum distributor is usually 55 idle, 127.5 main jet and 60 air correction jet.

There is also a 65 power jet in the right side of the carby - leave this one as-is.

The 34PICT/3 needs to be run a little rich to avoid flat spots with the 009 distributor - the extra fuel helps compensate for the 009s lack of vacuum advance. 55 idle, 130 or 132.5 main jet and 60 air correction jet is about right.

Also set the accelerator choke to provide full squirt when using the 009, and that squirt should be straight down the throat without splashing on anythin on the way - you can twist the delivery tube a little to get this right.

Oh - and are you using gasohol/E10 or any fuel with alcohol added??? This will make the VW engine run very lean .

Ethanol contains 39% used oxygen, so E10 - 10% ethanol - makes the VW engine run 3.9% lean, which makes it run very hot and this makes detonation/ pinging worse. If you HAVE to use E10, you need a main jet 2 sizes larger - for example from a 127.5 to a 132.5, or a 130 to a 135.

If you've filled up at one of those Syndey stations which lace the fuel with up to 20% alcohol (and don't tell you how much!), then the engine will be in trouble - it may not want to start at all.

VW engines can't adjust themselves "on the run" like modern computer equiped cars can, so you MUST change the jet sizes if you have to use E10 or MTBE laced fuel.

Woolies PetrolPlus causes a similar problem. If has up to 7% MTBE which also makes the engine run lean, though not as bad as 10% ethanol does. You MIGHT need a main jet one size larger, or it might be OK with the normal size (127.5 with a vacuum distributor - 130 with a 009).

This ariticle on my web site will help you check the tune-up with the 34PICT/3.

http://www.geocities.com/aussiebug1970/34pict3.html 

[Edited on 27-2-2003 by aussiebug]

Whoa.......Bill Shakespear or what !!!

Wow

Thanks Guys. Thats fantastic. I'll work through all of that in the weekend.

I must admit I have a pulley that has an unsual array of marks so I've been comparing the notch on the crank to the position of the TDC on my knackered 1500. If I could get the pulley off it I would use it as I know where TDC is and 7.5.

I'm in NZ and have no idea what they stick in our petrol... except that most of it isn't petrol, it's full of other crap!!

I'm also not sure what jet sizes I have. I'll see what I can find out about this. Is it a simple matter of remove one jet and replace it with another?

I've read your article AussieBug on the tune ups, thanks.

Blue74l, I'll have no idea what my CR is, hopefully stock (ish). But I'll have a look for air leaks.

Thanks
Jeremy

Cool dude

post again when you have more info and you will have her purring!

If you didnt build the motor you HAVE to ASS-U-ME that it is stock CR.

IF all else fails then we will work on that.

Robs site is BRILLIANT read through it and you will havre it sorted!

try using the top unleaded shell optmax and see what happens i had a ping and that fixed mine all the rest is crap fuel
greedy

hey
yer the fuel problem is a big factor the octane l;evel of the fuel of unleaded is down around 88 instead of 95 which causes early detenation and causes pinging etc!!
cheers
rhys

a stock 1600 shouldnt need premium unleaded to run guys.

yer i know but the quality of fuel at the mo is just fukin ridiculous!!!!
cheers
rhys

Sorry, aussiebug; the stock 1500 dizzy _is_ an "SVDA," which stands for Single Vacuum Double Advance - i.e. it receives advance from both centrifugal and vacuum. It is not the SVDA as sold by CIP; which is recurved to 009 specs and has a large vacuum canister as well - to get the benefits of both - but it is still an "SVDA."

If your static (or initial) advance is set correctly, I would look for another cause for the pinging: as the carb seems to have been eliminated, a strong possibility in an "old" engine is simply coking. If you are working on a budget, you can pull the heads and simply scrape as much carbon (or coke) from the combustion chambers (and piston tops as well, if you're careful not to get it where it shouldn't be) as possible with a wooden tool (say a tongue depressor, or a stick,) wash them in a solvent (such as petrol) and blow them off with compressed air. It's a good idea to oil the valve train well before re-assembling - no matter how careful you've been.

[Edited on 28-2-2003 by 70AutoStik]

you been playing with the chemistry set again? What was your analysis?

I filled up at the shitty little 2 pump servo at windang caravan park last week. As good as ever and (relatively) cheap too.

Dont watch a current affair/today tonight/60 minutes. Those shows rot your brain.

our teacher in the subject of power mechnics (lawn mower engines etc- but has a brother in a racing team mechnic and he himself is a really really good mechnic) said it to me and told me all about it
and yes i agree them shows kill you!!
cheers
rhys

my engine runs a lot better on pulp, especially during the summer. its only 7.3:1 static with a near stock cam (v-force ap2). it runs cooler and more consistently on pulp

If coking up is a problem it would be easier and cheaper to
put PULP that has cleaning agent in the fuel to clean it up.
Alternatively water injection will clean up the carbon.
Still if you have plenty of time then it would be good to check the compression ratio with a head off.

70autostick said:
>Bummer you got the vacuum-only dizzy, but I've owned three 60's VWs, have worked on a number of others, and my best mate was a VW mechanic for years (and I have several manuals) - and most 1500s had centrifugal and vacuum advance. Rip that dizzy out and replace it with, say, a 1969 Kombi dizzy, and you'll be wrapt with the results!


Hmmm -

The 61-64 distributor is VW 113 905 205A - vaccum only with 10 deg advance at 1.3" hg, and 15021 deg@2.8" hg

The 65 had the VW 113 905 205L which was vacuum only, 5-11 deg @ 1.3" hg, 23-28 deg @ 3.5"hg

The 66-67 bug had the VW 113 905 205K/L - vacuum only 17-19deg@1.3"hg, 24-28 deg@3.2"hg

The 68 had the VW 113 905 205M, Vacuum only 17-19deg@1.3"hg, 32-35deg@3.2"hg

The 69-70 had the VW 113 905 205T, vacuum only 17-19deg@1.3"hg, 32-35deg@3.2"hg

So I'm curious how you had double advance distributors in the 60s.

And re the "dump it for a double advance model" comment - my 70 bug with the SVSA has been absolutely reliable up to the point where the car got squashed by a nasty Ford (the engine was still running with a cracked distributor cap after the crash), it had VERY smooth acceleration and my log book tells me it got an average of 36mpg over it's 248,000 miles and almost 40mpg at a steady 60mph (100kmh).

So I don't see any reason for changing it (after I get that car back on it's wheels).


I'm happy to try other distributors just for fun, but the SVSAs work very well.

Thanks everyone

We'll I've double checked the TDC for no.1, so I know that the timing and valves are set properly. Also checked the rubber boots on the intake manifold- all okay.

I havn't gotten any further than this though as I pulled out my interior to see how bad my rust is. Not too bad , but lots of previous repairs, which are all still okay- only cause they were covered in that nasty sticky tar spray on stuff...yuck!!

So when I get all that off I can get the bits repaired and then POR-15 it all.

Anyway I think I may check the manifolds where they meet the heads, as when it dosn't start first time (and you sit there cranking it over) there is a definite hiss. Perhaps sucking air in? Or worse blowing air out. I would have thought that the head would be loose for this to happen though, and I havn't got the distinctive clapping "I've got a loose head" sound. Either way I guess I'll have to pull it out of the car to have a closer look.

Cheers
Jeremy