International Lancia Forums

Hi there,

my name is Martin and I'm in the possession of a Fulvia Coupe Rallye 1.3 from 1968.
When I acquired it at the end of last year, the engine did not run perfectly but I could take it to it's new home on own axes (which was a distance of about 600 km).

When I said, the engine did not run perfectly, I meant
a) a high fuel consumption (about 10 Liters / 100km on the highway)
b) kick-downs as well as high rpm's caused dark clouds to come out of the exhaust
and c) after arriving at home and approx. 10 minutes idling the engine compartment began to smell of fuel

According to above "facts" I thought, the engine needed some adjustment on the ignition and on the carburettors. They are from the type SOLEX C35 PHH2 and I bought a repair kit for them from Ebay. The repair kit consisted mainly of the needle valves, top cover gaskets, acceleration pump membranes and gaskets and some other items. Spindles or throttle valves were not included.

After disassembly, dismantling and cleaning of the carburretors I replaced all items that were available with the repair kit. I replaced also the spark plugs with NGK BPR 7E. Then I re-assembled the whole system and made a test run... I mean I wanted to make a test run but the car was really reluctant to start.

Also today, after hours of trouble-shooting, I'm not in the position to detect the problem and therefore I please you to give me some hints.

In order to limit the range of failures I can give the following info:
- ignition timing (10° before TDC) should be ok. The challenge in this discipline is to find the mark for the TDC on the flywheel (I disassembled the starter and found a red-mark behind the teeth of the flywheel but I cannot say, if this is the TDC or the trigger time-point. I assumed the marking to be the trigger time-point and adjusted the distributor accordingly by means of a strobe)
- contact closing angle is approx. 55°
- the carburettors are synchronised by hand (a better synchronisation shall follow, when the engine will run stable)
- idle valves are screwed in completely and then turned out a half round each (this was approx. the situation before my overhaul works)
- When the spark plugs are dry, the battery in good condition, and I am patient enough the engine will start after cranking at least 30 seconds. For this procedure the choke must be competely engaged and at no time the throttle valve must be opened. When running, it is very hard to keep the engine alive. At idling speed it does not last long and the engine stops with too much fuel inside. After that a new start is not possible (engine flooded) until the sparks had been removed and dried.

I think, too much fuel goes through the carburettors, but why?
How can I adjust the setting of the float gauge inside the float chamber that it operates the needle valve correctly?

regards,
Martin

Welcome Martin

Click here to read one of my earlier postings on the Solexes.
It applies 200%.

It may be something simple, but chances are that the previous owner also fiddled with the carbs. Perhaps even the owner before him. There may be wrong parts or parts missing (like the tiny steel balls under the weights, which act as valves for the acceleration pumps).

Some boy scout may even have drilled jets. You don't have the equipment to check all the bores.

Did you check fuel pressure at the input of the carbs?

Gunson makes a low cost meter (appr 20 euro) to check fuel pressure among other things.

Huib

Yes, I agree with Huib; this could well be a fuel pressure problem, or faulty needle valves or (also possible) incorrect float height.

Try running the engine (or at least cranking it over) and quickly remove the tops of the carburettors. You will then be able to see the fuel level. Unfortunately I cannot remember the correct height for this. The level can be reduced by VERY CAREFULLY bending the aluminium strip that supports the floats so that it contacts the supply needle valve sooner.

Paul

Hi,

first of all, I'd like to thank you for your quick answers.

I meanwhile went on testing by myself, and as a first approach I tried using the old sparks (the ones, which were mounted, when I bought the car). They looked very sooty and used but the car started immediately and ran more or less stable at idling speed.

As I wrote in my previous posting, I bought the NGK BPR 7 E, because my dealer told me, this were the successor of the BP 7 ES, as recommended on this site. In trueth, the "R" inside the model designation means "resistance", which must be considered as ko criteria for a Fulvia engine. So, I will now go and buy the right ones...

Of course, I will follow your hints regarding carb assembly and float level, because I have also doubts about their correctness.
When I take a look inside the carbs (air box is dismounted), short time after stopping the engine, should the tube be dry or is a low level of fuel on the bottom of the tube ok? The fuel comes from the acceleration jet in the center of the tube. After stopping the engine, some of the four jets keep on dripping a little.

regards,
Martin

The float levels are listed in the specifications book. This is on cd Fulvia_S1_1 available on thise site. By buying it you help support the site. Click here to go to the page where you can order the CD's.

I must caution against bending the floats. If the floats leak no amount of bending is going to get it right. If the floats are correct, the problem is elsewhere. Once bent it is extremely difficult to get them exactly right again without the proper jig. If you want to go the way of fiddling with the float level, you may consider putting washers under the float needle.
Someone may have bent the floats before. In this case you could as Paul says try to to bend them a little. If things improve, consider to get new ones in the end.

The pump jets are way down the throat behind the venturi's. If these leak the steel balls and/or the weights may have gone missing. If you take the cover off there are plugs near the rear (towards the manifold). Under each plug should be a weight (small hexagonal rod) and below the weight a small steel ball.

If it continues to drip, this does suggest that the float level may be too high; Huib's suggestion of putting an extra washer under the needle valves is an excellent one; try this and see if the dripping stops.

Paul

And don't forget to check whether one or both of the floats have tiny holes in them or cracks and are simply filling up with fuel and sinking to the bottom of the chamber. If I were you, I'd put some energy into finding new floats just to be sure.