Technical Bad coil?

[bugsymike]

Ok, so I'm going to replace the condenser, but it's ridiculous to buy online and ship for what is about a $4 part. Looking for one at a local parts shop, but not sure what the specs are. Anyone in the US have a suggestion? Hoping to get something at advance auto parts, etc.

Attached a couple pics of the distributor, which I think looks good.

Excuse the pun, but it would be pointless not to change and correctly gap a new set of points whilst fitting a condensor .
Back in the good old days pre electronics and ECUs, I used to boast (rightly) that if I went out on a breakdown unless the car had a massive engine failure (con rod through the side of the block) I could get them going so they could drive home .
One of those "tricks" was if it was misfiring due to condensor failure I would clean and gap the contact points and if I didn't have a correct condensor with me, often as not the car would have a radio suppressor fitted to the coil on the switch (power) side , I would simply reconnect the radio suppressor to the CB (contact breaker side) where it would act as a condensor for the points and disconnect the original duff condensor. The car would then start up happily and drive home.
The point I am making is providing the points are clean and gaped correctly and you disconnected the old condensor, then any similar condensor or small radio suppressor would prove or disprove your problem and it would not have to be inside the distributor, but nearer to the coil if connected correctly.
Incidentally if coil is marked - and + rather than sw and cb the principle is the same, whichever is the earth on the battery is the side going to the points.
Finally is there any damage "tracking or cracks" in or on the distributor cap, usually this starts as an occasional misfire in damp weather and gets worse to the point of stopping the engine.

 

[Toshi 975]

Condensers have always been a mystery to me even though I know what they do and my late father was an auto electrician. According to the Haynes manuals the 500 Condenser rating is 0.15 to 0.2 micro farads and the 126 is 0.25 micro farads which surprised me as the ignitions are pretty much the same. When an old Fiat dealership closed down and the parts store was being sold off I consulted an electronics expert I know and asked how the variations in condenser rating would effect the ignition and he said it would be negligible so I plunged in and bought a load of condensers for my “parts dept.” They are rated at 0.2 & 0.22 micro farads, need a longer screw to mount but I have had no complaints from owners that are using them. So in-line with what Mike has said.


The official applications for these cover a whole range of old makes and models but mainly Fiat cars from the 850 right up to the Strada. Also being Lucas they are a very good make. Should it be of interest the airmail postage to the US would be about £10.

 

[F30Msport]

Changed the condenser and it's alive!!! Amazing that it was down to that tiny little thing.

Thank you guys for all the help.

 

[bugsymike]

If coil is proved duff fair enough.
I would say if you are still on points and condensor as original setup, personally I have fitted literally a hundred condensors along with contact breaker points to every one ignition coil. The most frequent cause of an ignition coil failure on a points type system is people leaving the ignition on whilst checking something else and causing the coil to overheat and die! If that is the case it usually does the points and condensor also at the same time.
Re timing issue as has been mentioned not unless distributor was loose. However I have seen the cap fitted badly onto distributor and of course more commonly the HT leads on wrong.
Again on thinking back about coil failure, only one springs to mind , a Ford Mk3 Zephyr four that had an occasional misfire which I could duplicate by banging the coil with my fist as it had a loose/broken wire internally.
Shorting down the neck of the coil due to dirt and damp can give a misfire, but not normally stop it dead.

Another Gold Star for old mechanics.
I recall a guy coming to me with a badly running camper van asking for a quote on a new engine many years ago having several other garages price around £1000 or so. I listened to the engine, then told him to nip to the stores and get a a set of points and a condensor, all I charged him was £5 for my time and the van ran perfectly. All this explains why I don't drive a Rolls Royce

 

[F30Msport]

So...since I'm doing all this, I guess I should change the points. Can't find any guidance online or using the search function though.

 

[bugsymike]

So...since I'm doing all this, I guess I should change the points. Can't find any guidance online or using the search function though.

Yes!!! Change the points, have you got a new set ready? If you are not sure take some photos before removing them. The main thing is fitting any insulating washers in the original positions, the correct gap at the points and a little high melting point grease where the points touch the cam lobe. It really is 10 minutes work for someone familiar with it. If I had a dollar for every set I had fitted from when I was 15 years old I could probably buy your car

 

[F30Msport]

Got the points in, but how do I gap them?

 

[bugsymike]

Got the points in, but how do I gap them?

Fit them exactly as I said in my last post, then using a clean 15 thousands of an inch feeler gauge (or metric equivalent) inserted between the two contacts, with the cam lobe at it's highest point resting against the heel of the cam, use the adjusting/locking screw and move the points in that slot around their pivot point to get to where you can just feel the feeler gauge slide through the points. then carefully tightened the screw at that point and visually check you can see that small gap between the two contact points with screw tight. If you then turn the engine pulley by hand you should see the points close and as you keep turning the pulley they should open again.
It is important to assemble it exactly as it was before including all insulating washers and wires etc.
If I took more than 10 minutes fitting them as a 16 year old I would have probably got the sack!

 

[Bleeding Knuckles]

Hi F30M, depending on your distributor the gap should be as follows - (500) .019 to .021 in or 0.47 to 0.53mm - (126) .018 to .021 in or 0.47 to 0.53mm I would download the Haynes Manual from this site and read up the exact method for these engines. I generally set mine at .020 in but that is with a later 126 dizzy.
Ian.

 

[bugsymike]

Hi F30M, depending on your distributor the gap should be as follows - (500) .019 to .021 in or 0.47 to 0.53mm - (126) .018 to .021 in or 0.47 to 0.53mm I would download the Haynes Manual from this site and read up the exact method for these engines. I generally set mine at .020 in but that is with a later 126 dizzy.
Ian.

Always best to have the correct points gap, though if the timing is set correct I challenge anyone to notice the difference between a car running with 15 thou or 25 thou points gap.
Note I said timing correct, as if nothing else is changed the wider the gap the earlier the points open thereby advancing the timing slightly.
Which is why when a car with points becomes due for a service, it is common for the points to have closed up slightly retarding the ignition and taking the edge off the performance.

 

[Bleeding Knuckles]

Hi BM, with respect I wouldn't notice the difference between a setting of 15 or 25 thou either. But, even if the setting of the gap was at 21 thou
it would be within the manufacturer tolerance. A setting of 15 thou would be outside of the recommended range, and as you mention it would retard the ignition. I'm all for getting things set correctly with these cars, and using a generic points gap of 15 thou may well work, while outside recommended limits.
Ian.

 

[bugsymike]

Hi BM, with respect I wouldn't notice the difference between a setting of 15 or 25 thou either. But, even if the setting of the gap was at 21 thou
it would be within the manufacturer tolerance. A setting of 15 thou would be outside of the recommended range, and as you mention it would retard the ignition. I'm all for getting things set correctly with these cars, and using a generic points gap of 15 thou may well work, while outside recommended limits.
Ian.

When I suggested 15 thou, it was before any one else came up with the correct tolerance as I didn't have any relevant technical spec' available and knew from experience that most older petrol engines would run at that setting.
Whilst I don't claim any specific Fiat knowledge I would point out it was me on on Oct.1st who suggested the condensor fault which proved to be the issue when everyone else was chasing coils.

 

[Bleeding Knuckles]

Hi BM, Again with respect, saying you didn't have any relevant tech spec is fine, but you went ahead and quoted a figure from your past vast experience that does not fit with the recommended settings. Would it not have been a better idea to obtain said tech spec before quoting and save a potential waste of time resetting the points when the true figure is discovered. All of the members of this forum community post help for others who from experience have cured the same fault or problem and we do it without point scoring too.
Ian.

 

[bugsymike]

Hi BM, Again with respect, saying you didn't have any relevant tech spec is fine, but you went ahead and quoted a figure from your past vast experience that does not fit with the recommended settings. Would it not have been a better idea to obtain said tech spec before quoting and save a potential waste of time resetting the points when the true figure is discovered. All of the members of this forum community post help for others who from experience have cured the same fault or problem and we do it without point scoring too.
Ian.

Hi BK, No disrespect intended, though I always try to respond in the same way I feel I am being addressed, hence any perceived "point scoring".
At the time no one had forwarded the correct data and in the absence of that, I suggested a figure that would work and even if it meant 30 sec to set to the factory setting at a later date then at least the owner would have had a running vehicle, which is what we were all trying to achieve.