Technical 123 Distributor issues? Or something else?

[Fayray]

Has anyone here had issues with their 123? I fitted mine without issue (apart from the plug leads needing to be fitted around the wrong way) and it ran well. I set the dynamic timing which didn't require much adjustment and things were fine. Then the other day I had the car idling in the driveway to warm up while I checked the mail. When I returned I noticed the idle sounded rough and when I tried to drive it was mis-firing or starving - very rough. I assumed it was my carb again as I had no fuel filter fitted and the idle jet got blocked recently as well. I removed the carb and gave it a good clean and refitted and then placed an inline filter just outside the tank and also one between the fuel pump and carb. This last one was meant as a temporary measure in case there was gunk in the line that might flush through. Now it wouldn't fire at all. I swapped to my spare 26imb carb and same result although it eventually fired but seemed to only run briefly on one cylinder.
I checked that the fuel was being pumped into the carb and the flow seems normal. I checked the tappet clearances (3 times), checked the coil (new) which seems to have the correct resistance and I am getting a spark. I tried a different set of plug leads and plugs too. But all I get when trying to start now is the occasional pop. It's like the timing is way out. I removed the 123 and refitted as per the instructions and still nothing.
I also tried fitting my old distributor (with Accuspark) in the position it was when I removed it but I really don't know if it's close to being in the right position and it wouldn't fire.
It seems the more I do/spend on this car to make it more reliable, the less reliable it becomes:bang:
Any pearls of wisdom?

 

[Hutbed]

Are you running the recommended coil (double type or Bosch blue)?

 

[Fayray]

Are you running the recommended coil (double type or Bosch blue)?

I did wonder about that. I couldn't get a Bosch Blue but had a new one with similar specification. I have tested the resistance (3.4ohms primary and 8.00k ohms secondary) which seems fine and I'm getting a spark from it. I have a Blue on order. According to my old multi-meter my battery is putting out close to 13v and I'm getting the same reading at the coil.

 

[fiat500]

What I would do is to go back to square 1; you now have too many variables which is why....:bang::bang::bang: Make sure the engine is at TDC and be certain which cylinder has the valves closed. Fit the 123 according to directions and turn until the green light goes on; if its already on when you start then turn it slightly clockwise until it goes off and then again very slowly anti- until it is re-lit. Re-check that your HT leads are going to the correct cylinders and give it a try without changing anything else. Your coil sounds OK and when I first used the system I retained my original Fiat coil for several weeks without issue.

 

[Bigvtwin996]

.............I assumed it was my carb again as I had no fuel filter fitted and the idle jet got blocked recently as well..............

Any pearls of wisdom?

your car has 3 filters already....
one in the tank, one in the pump and one in the carb....

they are service items and should be cleaned....
so that is something you should do as well as the other suggestions...

I would also do some double checking that something has not come adrift or such... if a car is running fine then suddenly runs rough then clearly something has changed.. it may be insulation on a wire breaking down and shorting a HT lead all sorts... it is a case of working through everything one by one..
So starting with the 123 setup etc then other basic engine variables (valve clearances are another usual)...
You can even rig up a small fuel supply to miss out the whole fuel system to the carb....

 

[Fayray]

Thanks for the suggestions gentlemen. I shall take a deep breath and go through everything again and report back.

I know the 2 extra filters is excessive and was a bit of an over-reaction to yet another (suspected) carb blockage. I'll probably remove the one from the engine bay.

 

[fiat500]

k.

I know the 2 extra filters is excessive and was a bit of an over-reaction to yet another (suspected) carb blockage. I'll probably remove the one from the engine bay.

In over 32,000 miles I haven't been stopped by a carburettor blockage. A short time ago I did stop and clean the main jet whilst out on the road because the symptoms made me think it was blocked, but I eventually found out the car was running badly because the air-cleaner lid was cracked and air was bypassing the filter.

 

[Vitesse]

Simple solution is to revert back to the original distributor and coil. If it runs ok then you have eliminated the fuel supply as a problem. Then you know it’s definitely ignition related. Then try your new coil with the old points distributor to eliminate the coil as a problem.

I know you said you have tried different HT leads but when I first fitted the 123. I noticed the spark it produced was so strong it was arcing through the insulation of the leads on to the rocker box cover, so I invested in some decent silicone leads to stop it.

 

[fiat500]

Simple solution is to revert back to the original distributor and coil.

Trouble is, he's got a stupid Accuspark fitted so even that doesn't get fully back to basics.:bang::bang::bang:

...but a good idea to bypass the chance that the sparky spark is causing the havoc.

 

[Vitesse]

Trouble is, he's got a stupid Accuspark fitted so even that doesn't get fully back to basics.:bang::bang::bang:

...but a good idea to bypass the chance that the sparky spark is causing the havoc.

Oi you can’t say that about Accuspark that’s discriminatory! Also favoured by some people on here. ? Any decent 500 owner must have a set of points and a condenser knocking around? Seriously though I would still revert back to the Accuspark if it was all running ok beforehand!

With fault finding. Rule number one, if you’ve changed something, then it’s almost certainly the cause. You would have to be extremely unfortunate to have all of a sudden bumped into a fuel supply issue! Not saying it’s impossible though! ?

 

[Fayray]

Oi you can’t say that about Accuspark that’s discriminatory! Also favoured by some people on here. ? Any decent 500 owner must have a set of points and a condenser knocking around? Seriously though I would still revert back to the Accuspark if it was all running ok beforehand!

With fault finding. Rule number one, if you’ve changed something, then it’s almost certainly the cause. You would have to be extremely unfortunate to have all of a sudden bumped into a fuel supply issue! Not saying it’s impossible though! ?

I did refit the old distributor but with the Accuspark fitted. I really couldn't tell if it was fitted in the correct position though, and it didn't fire or even try to. I do have another spare, untested distributor with points fitted. I guess I could try that.
I will also try Bigvtwin's suggestion of re-checking wiring. All of this started quite suddenly when the idle became rough while warming up and then under load it was really rough. It wasn't completely warmed up at this point and it had started and idled as normal.

Also of possible note, the spark at the plug is not particularly fat and is a bit on the yellow side

 

[fiat500]

Just showing my ignorance.

Oi you can’t say that about Accuspark that’s discriminatory! Also favoured by some people on here. [emoji848] Any decent 500 owner must have a set of points and a condenser knocking around? Seriously though I would still revert back to the Accuspark if it was all running ok beforehand!

With fault finding. Rule number one, if you’ve changed something, then it’s almost certainly the cause. You would have to be extremely unfortunate to have all of a sudden bumped into a fuel supply issue! Not saying it’s impossible though! [emoji47]

 

[Vitesse]

Also of possible note, the spark at the plug is not particularly fat and is a bit on the yellow side

Ooh that doesn’t sound right. The 123 spark is a really strong crispy white blue one.

As I said before I could see it arcing out of the HT lead down to the rocker box cover but also what really did my head in at first, but I could also see it jumping between the HT leads where they were touching, which gave some really odd symptoms. I assume you have tried the old coil with the 123?

As you have probably discovered already. You can’t manually turn the engine over with a spanner and get a spark at the plug with the 123, it needs to be turning at speed.

It’s nearly midnight here but I’m going to pop to the garage and just confirm which HT lead is going to which cylinder, as the 123 is currently sitting on my spare engine.

 

[Vitesse]

Ok number 1 on the cap is nearest the engine block and that lead supplies number 1 cylinder which is the one nearest to you when leaning into the engine bay, so nearest the fan belt obviously the other lead goes to number 2.

The photo shows where mine was set once bolted in and it ran fine before the engine was removed. Complete with a dead spider! It might be alive though, I didn’t ask!

 

[Fayray]

Ok number 1 on the cap is nearest the engine block and that lead supplies number 1 cylinder which is the one nearest to you when leaning into the engine bay, so nearest the fan belt obviously the other lead goes to number 2.

The photo shows where mine was set once bolted in and it ran fine before the engine was removed. Complete with a dead spider! It might be alive though, I didn’t ask!

That's great, thanks. I just went out and pulled the 123 out and refitted it, this time making sure cylinder 1 was about to fire (in my dreams). I assume in this position both tappets on cylinder 1 can be moved? I think I had it 180 degrees out hence the plug leads needing to be swapped. Did the LED thing etc but still nothing. Changed back to the old coil (which wasn't giving any resistance readings but was working with the accuspark) and still nothing.

So next I will try and refit the old distributor with Accuspark. To do this, if I have the engine at TDC with No.1 cylinder firing and fit the distributor with the rotor pointing towards the block will I likely be close enough for the engine to fire?

And if you do ask the spider about his health (he kinda looks alive) could you also ask if he has any insights into my problem. He looks pretty legs-on:idea:

 

[Vitesse]

So next I will try and refit the old distributor with Accuspark. To do this, if I have the engine at TDC with No.1 cylinder firing and fit the distributor with the rotor pointing towards the block will I likely be close enough for the engine to fire?

And if you do ask the spider about his health (he kinda looks alive) could you also ask if he has any insights into my problem. He looks pretty legs-on:idea:

Yes rotor towards the block, so it’s pointing at number one on the cap, when it’s fitted. If unsure take number 1 cylinder spark plug out and stick a screwdriver through the hole and rotate the engine about with a 17mm spanner on the end of the dynamo shaft, so that you get the screwdriver to get to it’s highest point, TDC, everything should line up. Rotor towards the block and timing marks. You should be near enough for it to attempt to fire up. If it literally coughs and splutters and tries to start then you know you are pretty close. Of course the timing marks on the fly wheel should be pretty much aligned as well at the same time. Normally if it’s 180° out it won’t even attempt to start, it will just chug the engine over on the starter.

 

[Fayray]

I'm still having no luck having swapped back to the old distributor. But confusingly - and I don't remember it being this way before - with the cap on the only way it can fit, 1 is the exhaust side and 2 is closer to the engine. The opposite to the 123 cap. I'm so confused now. Still no joy bar a few pops and whisps of smoke. Tried the plugs leads both ways too.

One other thing I discovered while rechecking the valve gaps is the No.2 rocker has quite a bit of lateral play along the shaft that all the rockers are attached to. It has about 1-1.5mm sideways movement. The others don't. It is holding its adjusted gap though. Could this be a contributing factor? It may have been this way all along and I only just picked it up. Everything else under the rocker cover looks fine.

 

[fiat500]

Also of possible note, the spark at the plug is not particularly fat and is a bit on the yellow side

Sounds like a description of me and I also find it hard to start up in the morning.

Your later issue where you have the cap the wrong way round...no worries just now as it possibly means the helical gear is fitted 180 degrees out; I have a similar contrasting arrangement netween two different engines, but both of them fire.

Now you are back to having a kick from the engine and as long as you're 100% that static-timing is good, it might just be that you have a flooded engine. When I once cocked-up and finally dried out my engine after making it drink water during cleaning it was a devil to start again. I removed the plugs for a few hours to let the cylinders breathe the petrol out and before refitting them I subjected them to a plumber's blowtorch (all carried out well away from the car and with an extinguisher ready). I then put them back in as quickly as I could; not easy when they were so toasty to touch. It was still a pig to start but eventually picked up a bit, dried itself out and got back to normal again.

 

[The Whitakers]

Yes rotor towards the block, so it’s pointing at number one on the cap, when it’s fitted. If unsure take number 1 cylinder spark plug out and stick a screwdriver through the hole and rotate the engine about with a 17mm spanner on the end of the dynamo shaft, so that you get the screwdriver to get to it’s highest point, TDC, everything should line up. Rotor towards the block and timing marks. You should be near enough for it to attempt to fire up. If it literally coughs and splutters and tries to start then you know you are pretty close. Of course the timing marks on the fly wheel should be pretty much aligned as well at the same time. Normally if it’s 180° out it won’t even attempt to start, it will just chug the engine over on the starter.

Just to add a vital bit of info here and potentially why you keep having to swap plug leads around etc but it’s maybe something you should consider doing during your fault finding. When number one is at the top ensure the valves are closed otherwise the timing is 180 degrees out as mentioned. You may be forever chasing shadows otherwise. Leave the rocker cover off until it starts firing ok so you can easily check...

 

[Fayray]

Sounds like a description of me and I also find it hard to start up in the morning.

Your later issue where you have the cap the wrong way round...no worries just now as it possibly means the helical gear is fitted 180 degrees out; I have a similar contrasting arrangement netween two different engines, but both of them fire.

Now you are back to having a kick from the engine and as long as you're 100% that static-timing is good, it might just be that you have a flooded engine. When I once cocked-up and finally dried out my engine after making it drink water during cleaning it was a devil to start again. I removed the plugs for a few hours to let the cylinders breathe the petrol out and before refitting them I subjected them to a plumber's blowtorch (all carried out well away from the car and with an extinguisher ready). I then put them back in as quickly as I could; not easy when they were so toasty to touch. It was still a pig to start but eventually picked up a bit, dried itself out and got back to normal again.

I'm not sure I'd characterise it as a "kick", more a small, muted "pfft".
I'll check the plugs and let things dry out as you suggest. I'm really not sure if I have the static timing close to be honest. I will have a fiddle over the weekend:shrug: