Hi gang!

Just bought my first Fiat 500 yesterday. It is a -69, in great condition, but with some minor problems. I will describe everything that has happened, and maybe you recognize something.

When I first went to see the car, it started and ran smooth with no problems. The seller had probably warmed it up beforehand. I bought the car, and started on the drive home. A 450 kilometer drive across Norway (lots of mountains). The car struggled with long slopes and I repetedly had to shift down to second gear to keep going. I guess my next question to you as a group will be how to squeeze a little more power out of the engine, but first..

Halfway home I still had not run into any problems, other than the small engine struggling with the hills. I decided to check the oil, and the oil was fine. I went back to driving, and after a while there was a cloud of smoke coming from the engine room. There were oil everywhere. I had not put the measure pin/thing all the way in, and oil was spewing out. Luckily it looked worse than it was, and there were plenty of oil left in the engine.

I drove on, but now things started to go south. It started «puffing» and jumping a little bit. Mainly when I let go of the throttle after stepping on it for a while. It got worse over time, but not to the point that I couldn’t drive it. It was ok, but of course I was worried. Also, there were backfiringf coming from the exhaust. I’m struggling with the english language here

Ok, so I got home safe. (Oh yeah, I stopped along the way and topped off the oil). That was yesterday, and today when I went to check on the car this is what I found. It is very hard to start when cold. VERY hard, but it starts. It is not very cold here now either. The car struggles with idle. It is still «puffing», even when idle, (it didn’t when I first bought it). I was poking around the engine while it was running, and found that the puffs were air escaping from a small hole in the manifold under the carburetor. This hole is shown in the picture. I find it strange that there is a hole there, but I don’t know these engines.

Ok, so summed up.. I am not saying that these problems are connected, but they might be, considering all the problems started after the oil spewing everywhere. Does this sound familiar to anyone? And what about that hole in the manifold (!)?

Thanks in advance!

Welcome Graabein
Firstly thats a tidy looking car. Secondly there's no problem that can't be fixed on this forum.
A standard 500 will struggle with hills so don't worry about 2nd gear. If I was you, as you don't know the history of this car, I would give it a good service. Clean plugs and check gap and condition. Replace oil and clean slinger. Strip and clean carb. Clean points and check gap. Check timing and valve clearances. If you need a manual just shout and we can sort you out. Likewise if you need help on any of these matters just ask.
Damian

Well done for getting the car home on that long journey. In addition to what Paolo has said I would check that the carb is seated properly and no air leaks at the base. Difficult to see from that picture but the small hole you refer to is proberbly where a small drain tube should be that may have fallen out.

Thank you

That sounds like a big operation. Especially checking valve clearances. Do I need to remove the engine from the car to do that?

I was hoping to maybe narrow it down a bit. What do you think of the hole in the manifold? Is it supposed to be there? With nothing connected to it?

My shortlist of things I need to buy for the engine is:
- Carb kit
- Air filter
- Oil
- Plugs

Anybody want to recommend a good webshop?

EDIT:
Toshi 975 - A small drain tube? Wouldn't that draw air into the cylinders? Anyone have a picture of what it is supposed to look like?

Drain tube.

Don't be put off valve clearance check - it's simple and very important on these tiny engines. Once you've mastered it it will be something you can check in minutes.
The engine will not run properly with screwed up clearances.
Read some of the recent posts this week on this forum to best describe method

Read "Technical problems with IBM carb" written this week to understand valve clearance

Luxe said:

Drain tube. View attachment 170076

Click to expand...

Hmm, never seen a drain tube in that location on other engines, but I've never had a 500. Normally a tapping there would be a vacuum pipe to the distributor vacuum advance.
Just had a thought, is the tube on your picture going to the inlet manifold or is that a little drip tray around athe carb?

Robert G8RPI.

Thank you for your advice! I will be back with followup questions

That drain tube does nothing but move the problem 5 cm down the engine block. And I still don't understand how air is not sucked into the cylinders through that hole, messing up the mixture. But if you tell me it is supposed to be there, I will believe it

g8rpi said:

Hmm, never seen a drain tube in that location on other engines, but I've never had a 500. Normally a tapping there would be a vacuum pipe to the distributor vacuum advance.
Just had a thought, is the tube on your picture going to the inlet manifold or is that a little drip tray around athe carb?

Robert G8RPI.

Click to expand...

I can't find a distributor vacuum advance on the distributor, though I agree that that would make sense.

The 500 does not have vacuum advance on any of the variations. I was always under the impression that that little tube was to allow the spacer/drip tray to drain. The spacer on the 126 engines (I have just gone into my workshop and checked all my spacers) does not have this tube, just a hole to allow the little drip-tray area to drain. I would suspect that the gasket could be leaking (there is a gasket on both above and below the spacer)--alternatively, maybe the spacer has a crack in it. When you get the carb overhaul kit, get a new spacer and the relevant gaskets.
As other Forum members have mentioned, adjusting the tappets is a fairly easy, engine in car, exercise. I would check the internals of the distributor to check that none of the oil sprayed around the engine has got into the distributor, where it could cause a 'misrouting' of electrical routes--it could also be fouling the points.
Well done in getting the car home---welcome to the forum, we are here to help each other--you will find it one of the best (if not THE best) Forum with regards to helping other members out.

Congratulations Graabein on a nice-looking car and for having the confidence to do such a long journey so soon after getting the car. Not many people would have been brave enough to do that!
The little pipe to drain excess fuel is a standard item and it has puzzled many people before. It is definitely nothing to do with vacuum advance as the engine does not have this.
I imagine that even a perfect engine would need to use second gear quite frequently in Norway. Quite often, on hills, you reach a point where you would like to lower the engine revs but the engine would find third gear too tricky!
Your car looks very pretty and it is possible that it has spent a lot of time standing idle and being admired. So your journey may have loosened or used up any remaining adjustment in items like the points and the tappets or the distributor position. So everyones' advice will be worth following.
I hope you will be doing lots more long journeys.

The drain tube is there to allow any flooded fuel away via the groove in the top of the spacer and the clearance on the carb mounting stud hole. Any leaking fuel from the carb drains via the separate hole in the drip tray. Either way they both dump the fuel directly onto the top of the cooling tinware. The drain tube has no connection to the inlet.

Thank you all for your help!

And thank you Toshi 975 for clarifying

When the engine "puffs", air is shooting out through that hole. I don't understand why.

See what I mean by the level of input from this Forum? In case you need it, there is a correct spacer (for your engine/carb set-up) on E-bay, number:- 131886815252. it is not very expensive , so I would recommend that you try and get hold of it. If you do purchase the spacer, check that both the top and bottom surfaces are flat before you install it (wet 'n dry paper on a piece of thick glass), along with new gaskets.

So.. I just thought I would drop a line on how things went!

I don't really know what was going on when I first drove it home. It must have been all kinds of gremlins being waked up and rattled by me pushing the car to its limits forcing it over the mountains. We'll just leave my first post for now..

After I first asked my questions, the main problem with the car has been that is has been VERY hard to start. I mean, V E R Y, hard! Nearly draining the battery on the starter every time it cooled down.

It seems to me that every question on this forum is being answered with the same advice, "check timing". But I can tell my fuel pump is not holding pressure, and my floatbowl is leaking badly, so I figured it had to be related to that.

After rigorously testing the pump, and looking at the carb, I finally thought, heck! I might as well check the timing. And.. Drumroll please.. The gap was way off. At least by 2-2,5 mm! And the timing was way off to, by a couple of cm even!

I still have problems with the float bowl dumping fuel all over my engine, and my fuel pump not holding pressure. But my car starts now!

I will be fitting an electric fuel pump, and I actually will be switching the entire engine and trans for a 650. But, if was fun to make it run and start smooth. Once I have replaced the float bowl gasket (and everything else, full carb rebuild), I will have two running motors

Remove the float and give it a shake to see if it has fuel in it. If it has you need a new float

I did that today. Had the carb all disassembled. No fuel in the float.

I have this utrasonic cleaner, and it is perfect for carburetors! I test-ran the carb on the car this evening after cleaning, and so far so good. We'll see tomorrow..

Another thing though.. It reeks of fuel under the bonnet. I thought it might be the vent in the lid on the gas tank, but I fitted a hose in the hole and ran it under the car. That didn't help.

I have checked everywhere for leaks. I can't find anything. Suggestions?

Although you say there's no leak and it's not the fuel cap, surely it can only be one of those things?
My original tank had a sneaky leak at the bottom, where the tank sits on the padding strips. They had absorbed moisture and corroded the steel so that although it looked OK it was porous. At first the fuel was seeping out so slowly that it was evaporating before I could see wetness.

I found out where the gasoline fumes came from. It was actually the fuel hose going from the tank to the filter. There were no actual leak, but the hose was saturated with petrol. I don't know if it was an old hose, or if it just was not made for fuel, but it felt kind of sticky on the outside with a strong smell of gas fumes. It looked and feelt like just any other fuel hose, black thick rubber, but like I said sticky on the outside. I switched it, and voilá, no smell of gasoline in the car!

I also installed an electric fuel pump. I didn't bother to remove the old one, just bypassed it. I had it fitted under the bonnet on the left side of the car, right beside the engine for the windshield wiper. It is kind of loud though.. Do you typically do anything about that?