Hi I have the non tuneable 123ignition with an non modified 2l type4 I’m trying to figure out the standard curves (on 9 at the moment) If I look at the documentation it states the advanced does not start until 1300 rpm but at idle Rpm I’m already at about 12 degrees. (Static timing set to 7.5 degrees) Checking a few rough measurements with vacuum discontented. 500rpm 7.5 (wire pulled on one carb) 1000rpm 12 2000rpm 16 2500rpm 20 3900rpm 30 Does anyone have any figures on the idle timing advanced with a non-tuneable 123ignition? Thanks
When you've set these up as per the instructions using it's light, you then have to time it with your strobe as per normal. If your tickover is too high when you've set the idle timing to 7.5 BTDC, turn it down with the big screw on top of the LH carb. Hopefully that will stop your extra idle advance. At the same time watch what's happening with the timing to confirm - it should be less advanced so get it back to 7.5. Now it should all work as expected. For a stock type-4 choose from the recommended air-cooled VW curves the curve with the least total mech advance. Hope that made sense!
Thanks Zed for the quick feedback. I have set it up with the green light, statically time to 7.5 Btdc. The idle speed is correct about 950rpm but it still has some advance already triggering. It seems once above about 500rpm the advance is triggering and it jumps from 7.5 to 12. At high RPM the advance seems correct for the curve 23+7.5 I’m just wondering if this is normal or is there is something faulty with unit or my setup! I’ll try to reset everything again tonight Thanks
If I set my 123 to 7.5* using the LED, then set the top-out advance using a strobe, idle advance usually ends up at about 10*, which I don't really care about.
That curve should work well for a type-4 that wants less full advance assuming you're going for about 30 and a type-4 likes 28?
Thanks for all the useful feedback. It seems normal to have some extra advance at idle, but my adjustment maybe a little bit out. I will retry tonight and try to achieve these figures Static with LED = 7.5* Idle = approx 10* Max = 28* Thank you
Idle speed of 950 rpm is maybe a bit high. Any stock distributor will be adding advance around 1000 rpm. I would try setting it a bit lower (850 rpm) but it really doesn't matter provided absolute max is 28 degrees from the static timing plus the 123"s advance.
That looks fine to me and if it runs well and doesn't pink I'd leave it like that. Lower the idle speed if your worried about the 10deg at 950 revs but it really doesn't matter.
Can’t remember which number curve I finished up with but I picked one that gave me max 28 btdc and about 10 btdc at 850rpm idle. The extra idle advance works well with the twin 40 IDF carbs as it means the throttle stops can be screwed out a little more to avoid any uncovering of the progression holes while still maintaining a decent idle speed.
I was at the 123 ignition shop at the beginning of the month picking up a distributor and coil for my 2.0 type 4 and I sent them over the following graphs from ratwell From this the 123 guys suggested setting it to Curve 2 on the selector switch and timing it between 8-10 btdc. Hopefully this will be of some help
I uploaded a load of data to the Sambahttps://www.thesamba.com/vw/forum/viewtopic.php?t=617242 These all come from the official VW engine service manual from around 1974 .
