Fail to install electronic distributor

[vm75]

Hello

I have a fiat 124 spider sport 1800 us version , with carburator, from 1974
She was running beautifully, but I wanted to change the distributor for an electric 123ignition, to see the difference

I mounted many of them before on my other cars, and always been happy about these products
This one :

https://zupimages.net/viewer.php?id=23/21/tc0c.jpg

But on this spider I have a problem, there are 2 green wires coming out of the old distributor, from the 2 condensers.
I just learnt that this system is made to adjust the advance from 5° to 10° to facilitate starting.
Knowing that I just disconnected them and thought at least the engine would start and I would try to figure It out this problem later.

I just installed the 123ignition electronic distributor yesterday, put before the old distributor on cylinder 1 ( timing belt side ) on tdc , followed the procedure to have the light, change the coil for an appropriate one compatible with Electronic distributor.
And now, the engine won't start

I have sparkles, good ones, I have fuel coming I can see through the carburator, I tried 50 times, no start

I don't know exactly how this advance system work.
I just followed the 2 wires coming from the old distributor, one is going to the born negative on the coil ( classic ) , the 2nd wire seems going to a relay which has 5 pins, next to the regulator current
This one :

https://zupimages.net/viewer.php?id=23/21/7ope.jpg

I heard a snap, typical sound of fuses or relay snapping, when I was installing the new distributor, and I'm quite sure I heard this sound was coming from the relay next to the carburator.

So i don't know if I did something wrong about the installation with the 123 ignition, or if one of this relay snapped and would be the cause of my problem.

If somebody knows this system I would be happy to understand how to deal with that, because I never encountered this before and I'm lost

Thank you !

[vm75]

Hello again

So i made it work but there is something I don't understand

It appears the problem was not at all linked to the relay problem like I thought

I did put the distributor on cyl 1 tdc on the mark near the crankshaft pulley before I installed the new electronic distributor and It never worked

So i searched for the tdc cyl 1without aligning to the mark on the pulley , so I'm far before the mark , and it runs now perfectly
900 rpm, and when I check the advance with a stroboscopic light I'm now right on the mark of 10° advance

In a nutshell, problem solved but I don't understand why the tdc cyl 1 doesn't align with the mark when I checked With the distributor with engine off , but It knows align perfectly when the engine is running

[18Fiatsandcounting]

I'm not familiar with the 123ignition, although I have worked on cars that had this. But, I think there may be two issues:

1. It sounds like your '74 originally had the dual points ignition system, which had two points (and two condensors) in the distributor. There is an "ignition mode" relay that switches between the two sets of points, depending on oil pressure and engine temperature. The "starting" set of points has an additional 10 degrees of advance. I thought that the relay was located in the relay tray above the passenger footwell, but maybe a '74 is different. I also thought the wires to the distributor were green (running points) and green/black (starting points). If you disconnect both, the engine won't run. So, at least one of them needs to be part of the ignition system, but it depends on the relay as to which one is active.

2. Your ignition timing might not be correct. When the engine is at TDC on the #1 cylinder, and the marks (holes) in the camshaft pulleys are lined up with either the pointer or the little raised "nibs" on the front of the camshaft housings, the engine is set to fire on the #4 sparkplug. It's just the way Fiat did this, although many other cars are different. If you have set it to fire on the #1 sparkplug, it won't be timed right so the engine won't run.

Did the engine run before you tried the 123ignition?

-Bryan

[18Fiatsandcounting]

In a nutshell, problem solved but I don't understand why the tdc cyl 1 doesn't align with the mark when I checked With the distributor with engine off , but It knows align perfectly when the engine is running

It looks like we posted at the same time. At any rate, it's good that you got it running. Which mark are you checking the timing against? The mark on the timing belt cover? And you're using the very small notch in the crankshaft pulley?

Here's how I time the Fiat engines: Remove the #1 spark plug, stick a screwdriver in the hole, and rotate the engine by hand until the piston reaches TDC based on the rise and fall of the screwdriver. Put it at TDC based on the screwdriver, and verify that the marks (holes) in both camshaft pulleys are lined up as they should be. If not, rotate the engine by hand one full turn and they should be lined up. Then set the distributor to fire on the #4 plug. Advance the distributor just slightly. The engine should now run, and then I set the timing to reach the full advance of 36 or 37 degrees at 3500 rpm. I use a "dial back" timing light for this. I also verify that the timing advances as the engine is revved, and that the timing at idle is somewhere between 0 and 15 degrees BTDC. At idle, the timing doesn't need to be exact, but you do want the correct timing as the engine is revved.

-Bryan