You're welcome, I just want to see your car sorted so that you can enjoy it.
I'm glad that you're taking your time in trying to determine what is actually wrong rather than as our American friends refer to it as 'firing the parts cannon at it' i.e. continually changing parts until the fault is cured or even worse, calling it a day and abandoning/selling the car.
I agree with not rushing to buy parts that might have nothing to do with the cause of the problem. Much cheaper to borrow than buy - if it fixes the problem, great - if it doesn't, then no big deal, just return the borrowed part.
The reason I included mention of the 126 Ignition set from FD Ricambi in the NL was it seemed to be very good value for what was included, pretty much all the ignition service parts were included. I don't know if Ricambio (in the UK) has a similar kit, but probably best to stick with a U.K. supplier -with the dreaded 'Brexit' rapidly approaching, importing parts from European countries might be about to become slower/more expensive for those in the U.K.
(Here in Ireland, we've always had to import everything, mostly from the U.K. so have had currency exchange rates and delays in delivery to contend with forever :bang:
It was good that Ricambio were willing and able to give you some suggestions.
My suggestions, following on from their advice, would be to:-
1) check that the contact faces of the distributor point are clean and unburnt.
It's normal for a 'pip' to build up on one contact and a corresponding
hollow to form on the other contact. It's usual practice to remove this pip
using a small flat needle type file if you have one (there used to be special
'points files' available, but I haven't seen any for sale in decades...), or
use some abrasive paper (wet 'n' dry) folded on the double to clean both
contacts at the same time. Normally you'd just fit a new set of contact
breaker points but, for now, cleaning them should suffice.
2) Turn the engine until the points are fully open. Measure the gap with feeler
gauges, you need a gap of 0.012 inches (0.3mm)to 0.016 inches(0.4mm).
If you don't have feeler gauges, improvise E.g. iirc a credit/debit card is
approx. 0.003, so 4 thicknesses of a credit card will be about right. Then
clean the contact points with a drop of petrol or alcohol or brake cleaner
i.e. to ensure they are free of any oil, abrasive dust etc.
3) Turn engine until points are closed, remove the spark plug leads and
attach them to spark plugs resting on the cyl. head or engine cooling
'tinware'. Turn on the ignition, and using a small screwdriver, flick open
the points - there should be a strong spark at both spark plugs every
time you do this. If you have a strong spark, refit the plug leads and
and spark plugs (if removed) and try starting the engine.
If the spark is weak, the problem I reckon is then either the condenser
or the ignition coil unit. The usual way of testing the condenser
is by substituting a known good/new one (be careful, some here have
encountered faulty brand new condensers). You should be able to utilize
a condenser from any older car for this substitution - it just has to be
connected to the connection on the side of the distributor/points and the
casing to earth - you can use wires with crocodile clips or even just twist
some spare cable to make the connections. Disconnect the old condenser
when doing this, so it's out of the circuit. If there is still no spark or a
poor spark with the replacement condenser, then it's looking like the
ignition coil is faulty, zero or poor output.
Re:- Ricambio's observation that it's unusual for the plugs to be getting wet with fuel yet are sparking whenever you check them?
I mentioned in a previous post that a spark plug requires a higher voltage, to fire when it's within the cylinder and under compression pressure, than it requires when outside the cylinder and only subject to normal atmospheric pressure. Normally, the ignition coil can produce more than enough voltage to fire the plugs under all in-cylinder conditions.
The old Champion etc. Spark Plug sandblasters used to have a connection for compressed air to mimic the under-pressure conditions experienced by the spark plug when inside a cylinder. - (If you're a young guy, you probably won't have a clue what I'm waffling on about
)
If I turned the pressure right up, the spark became poor and then ceased.
This might explain why the plugs fire when you check them but are wet with fuel when you take them out i.e. the coil has enough voltage to make them spark in open air but not enough voltage to fire them when under pressure inside the cylinders.
I wonder if you post a request for a loan of a 126 wasted spark ignition coil here on Fiat Forum, would anyone be close enough to you to help?
If a known good ign. coil allows your car to start then your coil is faulty, or alternatively if fitting your coil to another running car now results in it becoming a non-starter. Maybe there's someone on this forum, within a convenient distance who would allow you to try your coil on their car if you call round? Lots of helpful people on here, so you might get lucky.
Other possibilities - many technical colleges, auto-electrical repair centres used to have equipment to test ignition coils, often in the form of a large test bench which could also test distributors, dynamos, alternators, starter motors etc. - do you know anyone who works at such a facility. I've often found a local motor factors to be a great source of advice on who can fix/check out something what locally. (they'd probably want paying, though!)
Cheapest option :- Borrow a known good wasted spark type ign. coil.
Next cheapest - fit an original points type coil (possibly cheaper from a motor factors than a Fiat specialist but it'd hard to beat Ricambi NL price of Euro 31.5 for a genuine Magnetti Marelli coil.), buy a rotor arm and make/modify a plug lead to use as a coil to distributor HT lead.
A little dearer, buy a replacement wasted spark type ign. coil (direct replacement for what you have now).
As your car was converted from 500 to 126, are you sure the components that are fitted are correct for your car and compatible with each other. On Ricambi's (NL) website I saw mention of 2 and 15 Ohm resistor units in the ignition section - I wonder what they're for, maybe to use with 'ballast type' ignition i.e. ign. coils that run at lower voltage e.g. 9V.
I'm very surprised that no one else on the forum has responded to your thread. Might have been better to have posted this in the 500 Classic section - that where all the experts seem to 'hang out' - I'm only an amateur compared to many of these guys at least where the 500/126 is concerned.
(I'm relying on my memories of working on 500/126 almost 40 years ago).
Re:- trying to borrow a known good 'wasted spark' ignition coil and possibly a condenser, might be worth starting a thread in the 500 Classic section, explain briefly what you've tried and ask if anyone could oblige with a loan of a good W/s ign. coil or if you could bring your coil over to try on their car or alternatively if they'd call around and try your coil on their car and their's on your car or some other arrangement. They're very, very helpful over there in the 500 Classic section, AND many have fitted 126 engine in the 500.....
Hth,
Al.
