123 Ignition timing (replaced 0231 185 010 distributor)

[AudioGuy]

My car has been recently totally restored with an overhauled engine, FI pump (Pacific) and a 123 distributor.  My issue is the car idles at 1300 rpm and is too rich.  All of the emission boxes has been eliminated.  It as recommend and I have set the timing at TDC at idle with vacuum.  The 123 distributor curve has been set at 8.  According to the 123 distributor information, "If the Emission components is not functioning to factory specs, you need to change over to a different Throttle Body Vacuum pick up".  What does this mean and would it affect the high idle situation? 

[glenn]

Lean out the FI pump by turning the knob CCW-with engine stopped-and adjusting idle air. repeat to 800 rpm and cut air to 750.

[AudioGuy]

Glenn,

I have already done that to no avail.  I also checked the WRD and when hot no air is coming through air cleaner.  Cold start valve doesn't leak and power is applied only for a second when starter is engaged. 

[Raymond]

Which model is this and is it maual or automatic?  How low can you get the RPM with the idle air adjusment on the manifold before the engine starts to stumble? 

If the FI pump came back from rebuild, you may have to chase the adjustment a while to get it right for your car.  Also, you may want to go through the linkage adjustment tour a few times.   Getting the mixture and timing right is an iterative process.  Have patience and perseverance.  Once it's sorted, you'll be happy for a long time.

This may be helpful:  http://www.sl113.org/forums/index.php?topic=5003.0

[Cees Klumper]

Hi Mark - as to your original question, about the 'throttle body vacuum pick-up', a guess on my part would be that they are referring to the connection point for the distributor advance mechanism (which I think is still mechanical, not electronic). I may be off here, the car is not neaarby (in fact, I am in Washington and the car in France) and it's been a long time since I looked at how the 123 operates, but my memory tells me the vacuum input is mechanical, i.e. the same small diameter hose that 'powered' the original distributor. If the emissions stuff was removed, it could be that the original pick-up point for the vacuum hose is no longer appropriate and that's what they are referring to.
Maybe someone here who has a 123 unit without emissions equipment can post some photos of where their vacuum pick up is located.

[Naj ✝︎]

Hi, Mark,

The 70/71 US spec. throttle body has the vacuum port in a different location as compared to earlier cars and gives vacuum all the time that the engine is running.
You need vacuum at the distributor only when the engine is idling.
With the emissions equipment, this function was acheived by the vacuum valve located with the other relays etc.
One way to acheive vacuum at the distributor at idle only is to use this vacuum valve between the throttle body and distributor and switch it on and off using the switch on the throttle body.
The vacuum port on the Euro cars only provides vacuum at idling, and would be ideal id one could be found.

Also see posts by Bob Possell regarding this issue. I can't rememberr what he did in the end.

Hope this helps.

Naj

[Peter van Es]

Check this thread... http://www.sl113.org/forums/index.php?topic=9984.0;all

Peter

[ctaylor738]

If you can't get the idle below 1300 with the idle air adjuster, then the either you are getting "false air" from somewhere, or the air valve is bad.  What happens if you screw it all the way down?  What happens if you pinch the hose?

[Cees Klumper]

Now that I re-read this thread, I am thinking the 123 manual's advice to locate a different vacuum pick-up point should not really have to do anything with the idle RPMs? Because it concerns the vacuum input at other than idle. Whatever pick-up point you use, at idle they all give vacuum and it's at above-idle that there will be a difference.
So I would think the idle RPM speed setting difficulties Mflaten is having are not related to the use of an incorrect vacuum pick-up point.

[ja17]

Hello,

I have recently installed a 123 distributor and ran into the same issues. The distributor on the car has a vacuum retard set up.  The new 123 distributor has a vacuum advance set up.  If you set the engine to run at 30 degrees  BTDC at 3,000 rpms, then the idle timing is so far advanced at idle (15 degrees BTDC at idle)  that the rpm idle increases way too much. If you set the timing to be correct at idle then the timing  at 3,000 rpms is too far retarded. The 123 distributor does not cover this issue in their installation instructions.

Looks like a different venturi unit could solve the issue.

[wwheeler]

This may be way off, but is it possible you need to select a different advance curve on the 123? There are probably 15 or 20 to chose from. I can't remember from my manual if those preprogrammed curves are for both the advance and the retard vacuum advances. On my '68 with vacuum retard, the 123 I put in about 2 years ago had the exact same curve as the 051 distributor. I believe the curve I am using is #8. I will look at it tonight. 

[mdsalemi]

...so much for plug and play...

[Raymond]

Is anyone with a 123 coming to PUB 2011?

[wwheeler]

I did check the 123 manual and my curve is #8. I never had any problem with it not being exactly as the factory 051 curve. My '68 has the vacuum retard and NO emissions relating to the distributor. As of two years ago, there are exactly 16 curves in the 123 manual. Look on line and see if they have a curve schedule. Before you install the 123, you must select the correct curve for your model.