General 92 Uno idle problems... help!

[kert]

Hello,
Just bought myself a 92 Uno 70SL. I don't know what type of engine the European versions have, but here in Indonesia it carries 1372cc engine with carburateur. It needed some repairs, but they were mostly under the car and electrical-related.

One of the problem I can't figure out is that the car idles very roughly--doesn't go up or down radically, just very roughly. So rough that the car shakes.. sometimes it even shuts off and have to restart--actually it shuts off a lot on its own. Difficult to start when cold too. Now I've replaced the spark plugs + wires, distributor cap and rotor, fuel filter, the sensor in the carburateur, the air filter--I also tinkered with the fuel and air adjuster under the carburateur but nothing seems too work. If anyone can offer any suggestion, you're input will be greatly appreciated. I love the car, it kills me that it can't run smoothly.

Thank you and sincerely,
kert.-

 

[Enzo]

Take a look to your distributor...if it's the breakerless type you should have to replace the Hall sensor &/or the module which is bolted on externally!This is one of the most common failures...and I think one of the few ones!!

 

[kert]

Thanks for the tips man..
I will look into it as soon as I get a chance and let you know--I just hope I won't have to replace the whole distributor. There isn't much Uno garages here in Jakarta--too many Japanese cars[V]!

kert.-

 

[Spam0r]

y dont u fiddle with turn over screw and see if u can increase the revs that it turns over with see if that helps i run smoothly

gotta love the uno's

 

[kert]

So I haven't yet replace the Hall sensor and ignition modul as suggested (I want to be sure, they're quite expensive here..), but I have toyed with the turn over screw under the carburateur. The car doesn't idle rough anymore, but now it idles at 10,000 rpm. I don't think this is right...? With it idling at higher rpm definitely solves the rough-idle problem, but does it fix it...?

Now the car also has a really-really bad cold start problem. Even after its warmed-up it doesn't start at first try. So: rough idle + bad cold start problem + not so good hot start == ?

Should I start with the carburateur or ignition..? If anyone can help, i'd trully appreciate it ..

Thanks,
kert.-

 

[ndroz2003]

Hello Kert,

I'am Indonesian, and I have been using My Uno for 13 years, I will let you know a Uno special Workshop in Jakarta. Please contact me by e-mail. Hopefully could help your problem.

rgds,

Hendro. N

 

[kert]

So I've serviced the carburateur, it was cleaned and checked for mulfunctioned parts. They said everything was ok, "it was just really dirty" they said. It didn't solve the problem--shucks.. the rough idling remains. It started a bit easier however..

I guess next is the distributor--just like Enzo said previously. I had to be a stubborn idiot and tried something else [)] Not that I wasn't listening to your advice Enzo, guess that I just have to learn things the hard way [}].

I see the ignition modul, its square-shaped metal attached to the side of the distributor. But I can't seem to find the Hall Sensor... If anyone can give me a clue on its whereabouts..

I'll keep you posted...

 

[Enzo]

Don't worry if you tried with something different than I suggested, I'm not the Bible here!And then I think the carburettor cleaning is healty for your engine, believe it!Now, you replaced all the electric parst, as s.plugs,cap,rotor and the cables...of course you're sure the timing's correct,and the vacuum unit still good!I advice to check those things and then you can worry about module and Hall sensor!

 

[Peetie]

I agree with others that distributer is to blame...it may be the leads to the electronic module on the unit but i suspect it is the idle compensator unit...thats the circular unit (usually gold coloured) bolted to the front/top of the distributer body...take off the hose that connects this to the carb and gently suck the inlet pipe of the unit. If there is a resistance its ok, if you can suck air the rubber diaphram inside is burst and idle speed will be poor. The unit can be bought seperately here..and is quite easy to fit after distrbuter is removed from the car. remember when removing distributer to mark body and flange so you get timing right when replacing...

 

[kert]

took apart the distributor as suggested this weekend. i wanted to replaced the whole distributor, but the Fiat store said it was unnecessary. so, i decided to just take it apart, clean, and replace all the parts. i carefully marked everything too, so when i put them together it'll be exactly like the way it was. when i took it apart the parts were:

1. Distributor cap.
2. Distributor rotor.
3. The flat piece with magnet ring around the center (you'll see it immediately after you take off the rotor and its round plastic cover under it).
4. The vacuum unit (i think this is what Peetie meant, it is circular and has a hose that connects to the carburateur).
5. The Ignition modul, or in Indonesia we call it the CDI (the square-shaped metal with ridges on the side of the distributor).
6. The housing. Mine is still good the store said, because the gear that goes into the engine on the bottom is still good, and everything else on the housing is still pretty tight and solid too.

I replaced all of them new (except the housing). Parts cost me 128 Euros--which is a lot by Indonesian standard--all were Magnetti Marelli. Assembled them carefully. I even borrowed my friend's StratoboLight thing to measure the timing. However, the problem still EXIST...[xx(]. I checked the timing over and over again, took out the distributor again and checked if I assembled everything correctly--which I did, and I'm positive the timing is correct. Yet the problem remains... it took me all day and it didn't even solve the problem. it still idling roughly, and it still goes off on its own when the rpm gets really low.

its kind of frustrating, however i've commited myself to this car.. and i want to fix it. drives great on high rpm, it reached 135km/h on the freeway! but it stalls in traffic...

what do you think guys...

 

[Enzo]

Aaahhh...135kmh for a 1.4 litres Uno[:0][?]I think it's a poor performance for that engine, my brick-shaped Panda with the 1.0fire took the 150kmh line some days ago...and I wasn't driving on a slope!
Are you sure you set the timing correctly?I know the value for the advance's 10degrees at idle rpm...and then you should exceed the 160kmh as EFFECTIVE speed[8)]!Does your engine have problems due to an high mileage??

 

[Peetie]

Sorry to hear distributer repairs have not helped....we'll have think about it again and get back to you if we can figure it out...are all engine breather hoses in good condition and have you had the cylinder compressions checked????

 

[kert]

ugh. i sincerely hope it isn't the engine. it has 185,000 km on it--which i think is pretty normal for an 11 year old car. no, i haven't done cylinder compression test on the car, maybe i should..? i'm pretty sure the timing is correct. if the timing is no good, you should be able to tell even at high speed right? the car runs great on high rpm, no hesitation--not even a pinking, it just that it stalls on idle. there's a slight ticking noise that goes up and down with the rpm. i believe that's valves, which should be ok too. its not loud, you just can slightly hear it..

oh, 135km/h, that wasn't full throtle at 5th gear! |) i believe the car is still capable of going faster, the problem is, our freeway in Indonesia is not as big as yours in europe.. and jakarta is notorious for traffic jam, one of the worst in the world..[xx(]

hey guys, thanks for all the input and suggestions, almost forgot to say that..

 

[custard]

maybe you should step back from the problem and check for stupid things like a broken engine earth strap.i had a car that gave me no end of trouble and this was the cause.i replaced nearly everything before i discovered that[:0]

The Fiat Cinquecento
Fun While It Runs

 

[kert]

Sorry for the long absence... but here is the latest update..

After replacing everything in and around the distributor (the spark plugs, cables, distributor cap, distributor rotor, the flat magnet piece, the vacuum unit, and the module--or cdi--everything but the distributor housing) the problem still exist--the car still idles roughly and difficult to start when cold...

I found out that there is one more ignition part that I haven't replaced.. the Coil--the part that connects to the fifth/center cable of your distributor (the other four go to the engine) and stationed on the top inner wall on the right side (behind right side headlight, its square shaped) I believe this unit is the thing that actually generates electricity into the distributor. So I thought, I've replaced 90% of the ignition system right? Mine as well replace this too, so if it ain't fixed I know its not the ignition system..
Hence I replaced it, and voila, the problem WENT AWAY! Not completely though, its not running as smooth as I want it to be, but it you can definitely tell the difference.

But... after I drove it a few times a new problem surfaced..

The car idled at 700 rpm, but after it warmed up and after you put it under load, the idle jumped up to 1600 rpm and wouldn't come down. Turn the AC on and it went down to 1000rpm--turn the AC off and it jumped back up to 1600rpm, even higher sometimes. This affects the gas milage tremendously..

I'm confused, the ignition is all new, carburetor is good. Used to drive a VW Golf, and had a similar problem. But with the Golf it wasn't ignition/ carburetor problem.. it was sensor problem. Golf has an coolant temperature sensor and an idle air stabilizer valve. I thought that this has to be sort of similar. Its a 12 year old car, probably one of the sensors are going bad..

Well, turn out that there are two sensors that regulate airflow. Both of them are directly installed into the manifold side-by-side. Under and behind the carburetor (into the manifold). Follow your vacuum hoses and you'll find them. The sensor on the inside--the one closer to the center of the engine bay I believe regulates the automatic choke, for coldstarting.
The other one (the one on the outside), regulates idling--when you have AC or when you don't have AC. They must've gone bad. Sensors move consistently, and they have been moving consistently for 12 years.

I replaced both of the sensors and now the car runs perfectly!
It probably was never the distributor, just these two sensors. But I'm not sorry I replaced them though, therefore I'll never expirience the cutting out at high speed..

So, there's the latest update.. my Uno is good now and I love driving it.

Bravo Uno!
Kert.-

 

[Enzo]

I still don't understand if your car is equipped with a carburettor or a monopoint injection...in the 1st case you shouldn't have electronic controls, except for the auto choke adjustment...could you tell me the precise displacement of your engine[?]



Passion has no brands or models!

La passione non ha nè marche nè modelli!

 

[John H]

Originally posted by Enzo
I still don't understand if your car is equipped with a carburettor or a monopoint injection...in the 1st case you shouldn't have electronic controls, except for the auto choke adjustment...could you tell me the precise displacement of your engine[?]



Passion has no brands or models!

La passione non ha nè marche nè modelli!

First post:

Originally posted by Kert
Just bought myself a 92 Uno 70SL. I don't know what type of engine the European versions have, but here in Indonesia it carries 1372cc engine with carburateur. It needed some repairs, but they were mostly under the car and electrical-related.

Happy New Year, Enzo