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Coil wiring/Talbot Express/Fiat Ducato/etc. 1971cc petrol

14K views 12 replies 7 participants last post by  GMJ  
#1 ·
I drove the van home okay, although I knew the carburettor was needing adjustment. Got under the bonnet, then noticed some leads were untidy and tied them back. Trouble is, in the process I apparently knocked an LT lead off the coil. I put it back where I thought it belonged, but now I'm not getting a single fire when I try starting. BUT... I don't know if the problem is that wire, or the carb adjustment. I don't want to try putting it on the other terminal in case I short something out. I can't easily get at a spark plug lead to test.

The wire from the ignition is brown/white and goes to the positive; a yellow wire goes from the negative into a wiring loom; the wire I found dangling comes from the loom and is also brown/white so I put it onto the positive.

So, are these standard colours? Did I put it to the correct terminal? Would I be likely to damage anything if I tried it on the negative?

Once I know that I have it correct, I can tinker with the carb settings again. If there is anyone who knows about those as well, it might let me get it running today (I have ordered a workshop manual but it will take a few days).
 
#2 ·
Yes you have put the wire back on the wrong connector, the yellow wire could be for a rev counter.You need a power supply between the coil and the distributor.
I also seem to remember that those old carbs used to wear, they used to have kits for them but a replacement is best.HT leads are prone to breaking down and distributor caps will olso have minute cracks, or the spring in the centre got old, or too much carbon deposite on rotor arm. I could go on but best if you eliminate each in turn rather than waste money buying parts not needed.
plus they do not like running without the airfilter, prone to spit back. :roll: :roll:
cabby
 
#3 ·
Thanks cabby

So, on the coil, that would mean there is a brown/white wire from the ignition to the +post, and a brown/white wire from the -post to the distributor, is that right? I can't tell, because both wires go into the loom, one of them via some sort of junction block mounted on the front cross-member above the coil.


It has brand new rotor, distributor cap, HT leads, coil, fuel pump, fuel filter and air filter; after the previous owner put all that on, he tried adjusting the carb, but admits he did not know what he was moving. There only seem to be two easily accessible adjustments; one is a big thumb screw which I take to be the mixture; the other is a very sensitive lever attached to the throttle, even a sideways jiggle of that squirts petrol into the carb.
 
#4 ·
bump

Still waiting for manual to come...

I found that there was a very weak spark; today I have taken out the battery, charged it up, cleaned all the battery connections, and cleaned the earth strap connection.

The spark is now steady and stronger, but it still seems to me not as beefy as it should be.

However, I think it should be firing at least, so I am hoping someone can give me some general guidance on carb adjustments.
 
#6 ·
Thanks Steve

I've had that open and it looks very clean and dry, but I will try putting the WD40 on. Is that what they call the electronic module? Is it likely to become faulty (other than with damp?).

On the carb, is there a way to set the acceleration pump so that it is roughly right -- in other words, near enough to get it started? Also the idle adjustment screw -- how many turns out from seated for an initial setting?

I am still not getting a single cough from it. Plenty of smell of petrol, so I guess it is either immediately flooding, or a problem with the ignition.
 
#10 ·
Update:

A neighbour with better tools and knowhow than me got me going in about 5 minutes!

The brown/white wires both go on the coil positive -- the second one feeds the electronic module. He also noticed what I had not -- that the new HT leads were all only half on, they had not had the metal connectors pushed properly home. I was lucky that it had not conked out on me mid-roundabout!

Now I am only scratching my head over weird results from my leisure battery, so off to browse other threads on that.
 
#12 ·
There are two firing order's for a four cylinder petrol engine, assuming the vehicle is not modern as the ignition system's have changed dramatically. The most common on a conventional petrol engine is 1342.Piston's in number one and number four cylinder's are at top dead center together one on compression firing stroke, the other on exhaust stroke, you will have to establish in which direction the rotor arm is rotating and it's position when number one cylinder is on compression firing stroke, the high tension leads then should be 1342 in the same direction as the rotor arm movement there are various methods on establishing which cylinder is on compression post back if you need more help.