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Fri May 26, 2017 2:13 pm

asiab3 wrote: inhabor wrote: asiab3 wrote: inhabor,

I'm not sure your carb setup would be compatible with the vacuum retard.

When your car is idling, and you take the advance hose off the distributor, does your idle RPM change at all? When you use a timing light at idle and then suddenly take the advance hose off the distributor, does the timing change at all?

Let us know, and we can go from there.

No, no change after disconnecting the hose. If I put my tongue in the hose it doesn't suck unless I give a little gas.

Excellent answer, thank you!

So your vacuum advance is ported correctly, so you MIGHT be able to use the vacuum retard feature. But the dual vacuum setup was designed from day one to work with an idle bypass carb like the 34pict3. I don't know if anyone offhand that has even tried it with a dual setup.

I think it might pull your idle rpm down so far that you'll have to increase your idle throttle stop screws a lot to compensate. This might expose progression holes to airflow and ruin your throttle response.

Only one way to find out...
Robbie

Edit: it will also make cold starts much harder, since there is not choke to temporarily hold the vacuum advance open 5-15 degrees.

I would guess that at a minimum one might have to drill a bypass hole in the throttle plates to give more idle air volume. For most this is getting to be pretty extreme tuning. Most people just leave the retard can disconnected when running a carb that is not designed to work with it.

Fri May 26, 2017 3:06 pm

Wildthings wrote: asiab3 wrote: inhabor wrote: asiab3 wrote: inhabor,

I'm not sure your carb setup would be compatible with the vacuum retard.

When your car is idling, and you take the advance hose off the distributor, does your idle RPM change at all? When you use a timing light at idle and then suddenly take the advance hose off the distributor, does the timing change at all?

Let us know, and we can go from there.

No, no change after disconnecting the hose. If I put my tongue in the hose it doesn't suck unless I give a little gas.

Excellent answer, thank you!

So your vacuum advance is ported correctly, so you MIGHT be able to use the vacuum retard feature. But the dual vacuum setup was designed from day one to work with an idle bypass carb like the 34pict3. I don't know if anyone offhand that has even tried it with a dual setup.

I think it might pull your idle rpm down so far that you'll have to increase your idle throttle stop screws a lot to compensate. This might expose progression holes to airflow and ruin your throttle response.

Only one way to find out...
Robbie

Edit: it will also make cold starts much harder, since there is not choke to temporarily hold the vacuum advance open 5-15 degrees.

I would guess that at a minimum one might have to drill a bypass hole in the throttle plates to give more idle air volume. For most this is getting to be pretty extreme tuning. Most people just leave the retard can disconnected when running a carb that is not designed to work with it.
Thanks guys. I guess I just leave it the way it is.I have a good mixture anyway. I think.

Sat Oct 21, 2023 4:56 pm

I have a new SVDA ..
I cannot get the sob to fire.

Seems like there is an extremely narrow window to get it to fire.

Vacc hose is plugged. Points at .016”… Trying to time it at 8 btdc.
Using a test light. No luck. Watching the point for spark. No luck.
Trying alternates.. tdc, 5 after, 12 before… nothing works . Wont fire.

I want to set her on fire and roast marshmallows but not until i sent off a case of tanneriite in the cabin.

Sat Oct 21, 2023 8:07 pm

75 Westy FI noob wrote: I have a new SVDA ..
I cannot get the sob to fire.

Seems like there is an extremely narrow window to get it to fire.

Vacc hose is plugged. Points at .016”… Trying to time it at 8 btdc.
Using a test light. No luck. Watching the point for spark. No luck.
Trying alternates.. tdc, 5 after, 12 before… nothing works . Wont fire.

I want to set her on fire and roast marshmallows but not until i sent off a case of tanneriite in the cabin.
If you're at a complete loss as to where you are, pop the passenger side valve cover, rotate the alt pulley pulling the fan. Watch the intake valve close on #1 cylinder & then take a gander at your #1 plug wire at the cap tower.
Your rotor should be pointing at that terminal if all is synched up. If not, MAKE the #1 wire plug into the tower cap that that rotor is pointing at.......: )
start there then worry about the exact idle spark event in degrees after.......

Sun Oct 22, 2023 12:33 am

75 Westy FI noob wrote: I have a new SVDA ..
I cannot get the sob to fire.

Seems like there is an extremely narrow window to get it to fire.

Vacc hose is plugged. Points at .016”… Trying to time it at 8 btdc.
Using a test light. No luck. Watching the point for spark. No luck.
Trying alternates.. tdc, 5 after, 12 before… nothing works . Wont fire.

I want to set her on fire and roast marshmallows but not until i sent off a case of tanneriite in the cabin.

First check you have a spark, set points gap , or if it's an electronic distributor (with red and black wires) that you never connected the black wire from the distributor to the black wire on the coil and cranked.
If you did, the module is dead now if you did that even for a fraction of a second as the module fires as you power up and the transistor inside tries to short out the ignition power feed. The transistor is a faster fuse than almost any fuse you could buy.
I have done this. We keep Pertronix in business by having to buy at least two modules per install in a VW with the black positive ignition power wire on the coil.

Assuming you get a spark:
I would do the finding where the rotor points for number 1 cylinder procedure , especially if you change from a 009 without any vacuum advance, the rotor arm points 90 degrees different.

Sun Oct 22, 2023 8:11 am

Use a test light or analog meter to see if you have a pulsing signal on the #1 (negative (-)) side of the coil when cranking.

The #15 (+) side of the coil needs close to battery voltage when the ignition switch is ON and 11v +/- when the engine is cranked.

Sun Oct 22, 2023 4:01 pm

Battery is low again from trying.
Ive had to recharge it many times and will again.

12 at battery
11.8 at the coil +
(didnt test cranking bc i saw the battery is low)

Its run a week ago. Idled .. advanced it a smidge. Nice. Turned it off. cant get any fire now. so generally its right.
i resmoked the vacc lines and there is some feom the aux air disc, but otherwise tight.

Just cant seem to make it fire consistently.
In fact its scarce.

I put these points on it.
Have a spare set too.

8* btdc
Rotor lined with the dizzy line at 5 oclock
points set just before it sparks.
gapped .016 mm
vacc tube off/plugged
I think battery is 650 amp

Sun Oct 22, 2023 8:50 pm

Did you replace the points before the problem started or after?

You gapped the points when the wear block was on the center of the lope?

Mon Oct 23, 2023 7:36 am

I did gap the points at center of lobe..

New points near the end of the old 009 effort.
Then I transferred the new points to my newly purchased svda.

The points it came with look to be quality also, from germany.
I may put those back on and try it again, after another batt charge.

I had jumper cables on it from a v8 suv to boost the battery but it may have been too weak to matter.

Mon Oct 23, 2023 11:56 am

If it fires, it will start.
Just wont fire.

on times that it has been running, I have as ive tried to set the max advance (probably 6 times) .. i notice that the #1 will sometimes not mark. that is, the tdc mark doesnt appear with the timing light. comes and goes. i chalked it up to ign wires crossing.

but it will eventually mark .. as I advance the timing.
idles great!

turn it off. wont ever fire again until i repeat the static timing... and then it's a crapshoot, etc.

i may test my T2 switch also.
weather has been mid 70's plus .. so the cold start assist is offline, etc.

Mon Oct 23, 2023 3:03 pm

Engines that won't run without a significant amount of advance often are suffering from a big vacuum leak.

Mon Oct 23, 2023 3:57 pm

I hear you … i have a smoker.. and checked it.
There is some smoke from the Aux Air Disc…. seemed minor.
Otherwise didnt see any.

Cant find a spare spark plug to save my life ..
Thats what i get for cleaning up.

Here it is at 8 btdc.

Im thinking weak spark

The Erlich points on it currently.

Mon Oct 23, 2023 6:04 pm

Have you tried replacing the condenser, I have had bad ones cause strange starting and running problems.

Mon Oct 23, 2023 7:23 pm

Mile High Puma wrote: Have you tried replacing the condenser, I have had bad ones cause strange starting and running problems.

I will check the condenser.. even though its new.
I have noticed that the points sparks/arcs early on the lobe when it’s barely open. might be simple as that.

Mon Oct 23, 2023 7:38 pm

75 Westy FI noob wrote: Mile High Puma wrote: Have you tried replacing the condenser, I have had bad ones cause strange starting and running problems.

I will check the condenser.. even though its new.
I have noticed that the points sparks/arcs early on the lobe when it’s barely open. might be simple as that.

A tiny arc as the points just open is normal.

Tue Oct 24, 2023 7:58 am

charged battery…
12.7 on battery
12.5 on the coil

I guess i will shift focus from timing and spark, and look at fuel and air.
I think vacuum lines are ok. So… fuel pressure regulator?
Everything else is new.

I may have to take it to… ack… a mechanic. :roll:

Tue Oct 24, 2023 1:42 pm

I will gap the points bigger.. to .018-019”

I got confused between mm vs inch for a bit. Researched and found .016’’

But now remember the advice to go a bit bigger.
Gonna check fuel pressure if Auto zone has the tool.

It’s crazy Thats it’s Gone backwards.. was focused on the hesitation and now back to no start. Oh the joy!

Tue Oct 24, 2023 6:56 pm

What counts when starting, is the voltage between the #15 terminal on the coil and the ENGINE BLOCK while the engine is being cranked.

Wed Oct 25, 2023 2:51 pm

ok, I'll test that.

(I have a flamethrower coil on there.
i also have the original Bosch, which I haven't tested.)

Thu Oct 26, 2023 7:59 am

As nobody else has pointed it out - another thing that happens when you set up an engine to idle for the first time, is that you end up with the idle speed somewhere high enough for the distributor , either 009 or SVDA style, to be producing timing advance from the high engine speed.

Then the next time you start it, it runs slower, and the timing is no longer centrifugally advanced by the engine speed , so the timing drops back to the point that the engine stops.

So you need to be checking the idle speed properly and making sure its say 850-900rpm when you set idle timing, (vacuum hoses off and blocked from the carburettor end) or just go for 28-29 degrees (same hoses off and blocked off) when the timing stops advancing centrifugally up towards 3500 rpm.

You may have to keep adjusting mixture/volume screws on the carburettor, then check the RPM and the timing, and repeat..

Conclusion : You can only set stable idle timing with stock type engines well below 1000 rpm as the distributor will begin to add timing.