Hi,

Having crashed my last Uno START, i've recently bought an Uno FIRE, problem i'm having at the moment is cold running.
Initally starts up fine, idle is a bit variable and sometimes when accelerater depressed the revs drop off and it looks like the engine is about to stop, but then recovers, but generally will not run well til it has warmed up. I've found twice this week i've pulled out of my drive and as i would normally accelerate away, the engine dies off and cuts out. When starting it after the cut out, takes a while to get going and usually starts out at very low revs before building up. Once the engines heated up runs fine with no problems. Just wondering if anyone else has had a similar problem and how it was remedied.

Also can someone tell me are there any major differences between the START and the FIRE apart from the interior, as i'm using the crashed car for spares.

Cheers,

Ali

Just forgot to mention i'm gonna try flushing the engine through with some fuel injector/fuel system cleaner before changing parts.

FIRE only refers to the type of the engine, not the gizmos around.
Is your 999 Fire equipped with a carburettor or is it a SPI model?

Its SPI

mine's a carb and it does exactly that when it's cold. i keep it revving high with choke till it warms up

Hi Ali and welcome to FF

(CZ)enda, there was an Uno branded FIRE in the UK . I thought it was a carb version (before the days of SPI), when the 903 Uno 45 (Formula) was also on sale .

I’m not sure about the Uno FIRE trim level, but the SPI set-up is most likely the same as the START – perhaps with the odd revision. I’d guess it’s a different year, or has extras like clear front indicators, a tailgate release lever and maybe an odometer (S trim level).

On the SPI set-up with ruff idling the easiest things to check are over tight accelerator cable, a dirty throttle body, and bad vacuum advance. Let us know if you need pointers .

Sorry Killfr0g, I’m not so clued up on carbs. Hopefully Chas or Alex can point you in the right direction???

As I was reading, I was a little dismayed that it was SPi - I don't know about those, so follow Louie's advice.

Now as for carburettors - yes, that is a VERY COMMON set of symptoms! I would start by testing the vacuum advance unit. Pull the pipe off the carburettor, clean it, and attempt to suck on it (yes really, though I suppose you could use a hand-held vacuum pump, but then what would you have one of those lying around for? sorry, bad joke)

If you can draw air through the vacuum advance unit, then it's stuffed. It will be letting in that extra air with the engine idling, and so any attempt to open the throttle causes the engine to die because the mixture is just too lean.

I think this advice applies to the SPi version as well - as Louie said.
Also, make sure the intake manifold nuts are tight onto the cylinder head. I've heard of cases where these worked loose.

The carburettor itself (if it has one) is jetted very lean. I have found that the mixture adjustment screw (on the base of the carburettor, visible when standing on the right side of the car) has no effect. To fix this, you can enlarge the idle jet from 0.45mm to 0.5mm or maybe 0.6mm. The idle jet is a press-fit in a small brass tube that has a slot-head top (without air bleed hole) that you can see after removing the air cleaner.

Jet enlarging can be done with tiny drills purchased from an engineering shop and turned by hand with a pin vice (looks like a large jeweller's screwdriver).

Or, you can put in the 0.5mm jet from a Weber 32DMTE carburettor off an Uno 70, if you so happen to have them lying around.

Either way, jetting up the idle will allow the mixture screw to have an effect and should help the engine idle and pull away more smoothly.

Thanks,
-Alex

Thanks Alex,

That was great feedback!

I got the carburettor cleaned but still facing similar problem.
My garage fellow has exhausted his knowledge skills on finding
a way out

I would work on the tuning part you mentioned and see if it makes any
difference.


dhug9

i done all of this but the same problem

yeah same here, when it's cold it runs pretty badly taking it to a guy who works with the FIAT service centre over here

I'm actually liking the idea of fitting a 1.2 from a Punto into it tho!

Just mentioning. The SPi on the Uno works very well, and is not affected by weather temperature. Wheter it is +30C or -30C mine runs well. I´ve removed the cold air feed to the K&N-filter during winter.

Thing to check are already mentioned, but here´s my list:
Change fuel filter.
Change oil filter and oil to renew lubrication. This is of great importance during winter. Waste of oil to change oil and not filter.
Clean the SPi module.
Check the oil breather for free oil breath.
The advance unit should be tight. My Uno worked for 2 years with a faulty advance unit, so it won´t necessarily be this one.
Change air filter.
Check the thermostat so the engine doesn´t get coolant when trying to heat up.

Morten.

Very informative tips Alex

Mine is an Uno 45 carb. Same problem in the morning, It do start but need to be warmed up for around a minute or two then it's as good as new. I think it's normal to use the choke the first time you run the engine in the morning.

My Juan and only Uno. said:

I think it's normal to use the choke the first time you run the engine in the morning.

Click to expand...

Yes, it is. I drive with choke on until the engine warms up to 60 centigrades.

Some 45 FIRE were equipped with a gizmo to prevent engine from stalling when cold - it was called ECOBOX and if I understand right, they were supplied to continental Europe only.
The principle is rather complicated and I am not sure I understand it fully, but to cut the story short - I have one and compared to the non-Ecobox 45, it revs up much smoother when cold.
On the other hand, it does not have the dynamic of plain carb system after warmup - the engine is rather lazy and the top speed is some 10 - 20 km/h lower.

I have a 999cc FIRE with automatic choke and I've found that starting in the cold with NO revs works fine but with revs it tends to open the choke too much and take a long time back it down again, it also splutters into life rather than starting smoothly with revs...

Hope that's of some help to someone!

Still having the problem, turned out the head gasket was pretty much completely gone, so got that changed, but still same problem, not quite as bad tho. Also got another problem now, the whole car vibrates loads when idling, and even more with a little bit of accelerator. Just checked the vacuum advance by sucking on it, air coming through, is it not supposed to be? Wondering if the vibrating is due to bad timing? also waiting for a part so i can change over fuel injector unit, read somewhere that the sensors can bugger up and that'll bugger up the fuel mixture, got an old one so thought i;d give it a go. Only other idea i got at the moment is the fuel pump maybe. Any ideas from anyone would probably be useful.

Just to clarify, its a 999c Fire with SPi.

Forgot to mention something that worried me a bit, was wondering if anyone else with an SPi has a lit of all i can describe as clicking noises coming from the fuel injection unit?
Fast and regular, but don't ever remember hearing them before, thought it mite be a sign of something going with the unit.
Cheers

Hi AliBarnett,

A shot vacuum advance diaphragm causes the engine to idol roughly, like it’s running on 3 cylinders. That’s what happens when I remove the vacuum advance pipe .

I would fix Vac Advance before thinking about the fuel injector unit . Try blocking the pipe for now.

I’m not sure about the clicking. Possibly a short on the HT lead

Hi magicmonkey,

How tight is you’re throttle cable?

Regards,

i've been having similar problems with my uno. it's FIRE so it does not have a carb. i've noticed that more smoke is comming out of the exaust

Tomi - sounds a bit like a symptom/problem described by Monty Mort a long time ago - there is a throttle switch that reduces the frequency of the injector when the engine is idling (throttle closed).

I could be way off, but smoke coming out the exhaust sounds like maybe this switch is not closing (accelerator cable adjustment?) and therefore the ECU is injecting too much fuel by having the injector running at 'full' frequency.

Also, again could be way off, but that clicking sound mentioned by AliBarnett could be the sound of the injector operating at half-frequency?

As for those poor souls still trying to get the carburettors working smoothly, sorry I wasn't around to offer moral support back in December! It really should be possible to solve the hesitation when pressing the accelerator - it is because the idle mixture is too weak and drilling out the jet will definitely richen the mixture - but there are of course the other things you have to check first:

1. Ignition system - plug leads, plug condition, ignition timing (3-5 degrees without vacuum advance)

2. If pulling off the vacuum advance made no difference, that is not a good sign. There should be no airflow through the vacuum unit, so pulling the pipe off should make the engine run rough.

3. Check the badge on the back of the car - if it has four or seven letters, starting with F, the engine idling will never be very smooth.

-Alex

Cheers for the advice,

Gonna put on a working vacuum advance and see how that effects it.
As for cold running problems, my thoughts are either fuel injector unit, fuel pump or thermostat.
Anyway, another problem i've been having since the head gasket was changed is that instead of the usual 90 degree temp where the fan comes on, its now 95 - 100 degrees, checked coolant level, bled it, topped up oil level, no difference. Any thoughts?