International Lancia Forums

Did you try a new rotor? With the distributor cap off, the HT lead from the coil above the rotor(metal strip) and when starting, no sparks should be seen.

Interesting that it changed. I look forward to your report when you change capacitor and points for new ones. As Lucas suggests, how are rotor and cap?

In the meantime for what it is worth:
Bad starting usually indicates that points have to be replaced.
Problems on the carb furthest away from the fuel pump often indicate incorrect fiuel pressure. No one understands how this can happen. Just experience.

I've been hinking about this.

Car runs well on throttle? Just looses a cylinder on tick over. Seems to me that with worn carbs the butterfly can be shut on one cylinder and ok for tick over on another.

Easy way to check (but you need to take the carbs off) is to hold the carbs with throttles shut up to the sun (maybe wait for springtime if you are in europe).

One can reset the butterflys if carbs are not that worn by slackening the screws holding the b'fly to the spindle, the n fully opening the butterlys against the spring and let shut by letting go! Tighten up the screws and recheck into sunlight.

good luck - this may not be you problem but ....

Tim

today it is very sunny in germany.

He can start now to check;)

He would need a snorkle in the UK at present!

Tim

I went back to the first post and it seems this all started when the HT wires and spark plugs were changed. Then the floats were changed and then there were a cascade of tests and suggestions, some of which I offered so I'm not complaining but making the observation that when something goes wrong it's good to have a short list of possible variables to re-trace so as not to multiply the possible causes.

The wires seem to have been proven good so we're back to the entire ignition system; rotor, coil, condensor, cap, points, possibly the fuel pressure (which may not have been tested yet) and possible carb butterfly misadjustment, though if they have never been touched since the begining of this adventure I would hardly advise touching (synchronization screw) at this point. Could the new wires and plugs pushed the ignition system over the edge? Is there a particular type of wire required, resistor, solid core or such? I don't know enough about the different HT wires available and how they can affect the points system in the Fulvia.

ZanettiZA do you have a vacuum gauge? These will typically be able to measure fuel pressure as well. You would need to tee it into the fuel line into the carb and take note of the value as the motor is running.

Anyone up for a Skype engine timing session?

I replaced the point, condenser and coil... and the problem was still there... replaced the plugs and she started on 1/4 engine turn and ran beautifully. Checked No 1 and 2 plugs and noticed a small amount of oil No. 2, both had small amounts of oil at the top of the the screw thread, it looks like the Spectacle Gasket for No. 1 and 2 is a bit leaky, although this oil wasn't there previously. This cause the sparks to become fouled.

There isn't any oil there at the moment but the performance seems to be degrading bit by bit, checked the plug and they are lightly covered with dry black soot. I am guessing that this is causing the problem, a weak/bad bad spark hence the rough running.

I am again convinced that the mixture is rich, how can this be solved? Would anyone else agree with this?

Also, I have only been idling the engine, I haven't taken her out on the road yet since the spark plug change.

Good that possible ignition problems have been eliminated.

Are you sure there is no oil leakage through valve guides or piston rings? You say there is no oil in the plug holes now. Even if it was, it would not foul the electrodes. The plugs are designed to keep the combustion pressure in. They will surely not let oil pass.

As I said above I always send suspected carbs to a specialist who has all the tools and equipment to make sure the carbs are functioning 100%.
What you could do is simply measure the float level. Just take the cover off and measure the distance from the top of the bowl. The correct values for the various types of carbs are in the Technical Databook. Same book also lists the jets. You can check those too.

Did the car ever run correctly when in your possession or did you recently buy it in the condition it is in?

Thanks Huib, I get what you are saying about the oil passing through the plugs it just seems like a strange coincidence...

The car was running when I got it, not very well, the pump diaphragms were leaking etc... oil everywhere generally not good nick, she is much better now but the problem that I have described here was not there when I got the car.

Any thoughts on the black soot on the plugs or do you think its possibly oil? I know the head has been done so I assume its not an issue with that.

One more thing, according to the Technical Data book, the level is 19... I assume this is mm? where would it be measure from and to?

Are you sure that the chokes located on the top of the carbs are closing all the way? The control inside the car could be pushed all the way home and yet if the bar connecting the two chokes has not been adjusted properly they could be letting in enough gas to upset things. Unscrew the bar from the choke cable to insure it is fully closed.

Do you get a variation in the idle if you adjust the idle screws? If not that could signify that the spark plug is loaded and thus not firing the mixture OR that additional gas is entering the venturi either through a still opened choke or a mal-adjusted float level. A high fuel level in the car will cause gas to be pulled from the main circuit earlier than required.

How is your air filter? If it is very clogged it will cause more fuel to be pulled into the motor as it will cause higher vacuum. You can either replace it or temporarily remove to see if you notice a difference.