HELP! Uno 45s firebox owner on steep learning curve.

Uno put in for MOT last week, failed on emissions & rear brakes. Garage sorted & gave all clear, now less than a week later:
1.the engine cuts out when slowing for lights/slow rush hr traffic
2.electrics (indicators) fail go off & come back on again of own accord
3.fuel gauge has works intermittantly
4. fuel thirst-nearly 3/4 tank in less than 200 miles
5.windscreen wash doesn't 'whhrr' at all and can cause fuel economy gauge pointer (when it doeswork) to slam over to the left when wiper-wash toggle pulled.
Now are these problems all linked or do i have a carb problem and a loose electrical wire problem. have checked fuses & car is always better on return journey ie.crap this morning & fine but a little jumpy at lunchtime. Is it something the mechanic has done/knocked during MOT repairs or is it an unfortunate coincidence?
Looking forward to your expert diagnosis. G

As a first thing - Go back to the garage?

I assume you paid extra for the fixes, in which case you have a receipt.

Oh, and only start ranting and raving after a failed polite request.

But basically, the engine cutting out and poor fuel economy are the problems related to their work. The electrics you can regard as different problem (maybe ground loop or similar).

Also, 3/4 tank fuel for 200 miles does sound about right for town driving and/or lots of heavy throttle - or is it motorway driving?

Thanks ts86 thanks for your view on this, yes awaiting for garage to return phone message. I think the fuel usage is partly town driving as has have only 10 mile round trip to work & back rush hr traffi with manual choke on. What would cause the economy gauge to not work-haynes seems to suggest it works on a vacum?

My Uno has some comedy electrics too - one of the indicators loses it's earth connection, as do the wipers, from time to time (but only when it's raining...) - I solved the NS headlight by cleaning the connectors, but I havn't got to the others yet.

Not really fair to test the MPG on a 10 mile stop start run - but you should get 45 mpg on the open road (if you can find any...).

Gems, you have the manual choke on all the time? Is that to stop it cutting out or because the engine is still warming up? Sounds like a waay too long a time to have it out for.

economy gauge? You mean fuel tank gauge? No idea how that works exactly. Although once I had it fly completely south as I switched the ignition off. I screamed, knocked the dash and then it went back normal after I started the car again. Not happened since

Hi gems,

:wave: Welcome to the forum!

The 45S has an economy gauge - I think its connected to the Vacuum advance on the distributor, If the Vacuum Advance diagram is shot, or the pipe is perished, the result would be poor idling, and engine wanting to stall.

Chas has a 45S, and will be able to tell you more about the economy gauge. I have a 1.0 IE, so it’s quite different - I have loads of sensors to deal with... OK I do also have a 45S turbo look alike, but its new to me, and in Kent.



The electrical problems sound like a disturbed earth bank. As said, its behind the O/S head lamp, on the right as you look in the engine bay. – Loads of black wires with spade connector. Cut them off, replace spades and clean up the connector block and you should be OK. I did this on my first Uno after months of electrical mischief as you descried, the new connectors should be good for another 10 years - Shame the rest of my Uno wasnt

Kind Regards,

OK.

If any metres, gauges, needles etc. suddenly smacks the bitch up, it´s propably earth failure. Remember on the Ritmo Abarth (as usual when it comes to grounding / earth) the rev counter hit 8000 rpm when actually doing 2000 rpm in 5th gear. And so on... Many strange things happened: lights, wipers, radio - you name it. This was an earth block in the engine bay. I´m not sure where it is on the Uno 45.

Is your Uno fuel injected or carburett´ed? It may get too much fuel when idling, as this strangles the engine when stopping in traffic and red lights. This happened on my Uno - on every red light. Had to always give it a little throttle until I found the little idle plunger on the back of the injection module. No idle speed screw here. Just loosened the throttle cable a bit so the plunger was depressed when I let the foot off the pedal.

Morten.

thanks for all your thoughts about my trouble some uno-have just had a look at the spark plugs (perhaps one had blown would account for high fuel usage) and have 3 clean and 1 rusty. Is this why & how much will this set me back to set right down the parts shop?

its a carb engine-mechanic wasn't surprised about problems i've been having when I rang him- he's gonna have a look round the car Thurs so will keep you all posted!

Hi there,

Spark plug 2 is harder to change and is all to often missed. The Air box gets in the way. – My Uno had a different plug 2 when I first got her .

Avoid Champion plugs like the Plague – And Haynes manual is Wrong – electrode gap for FIRE engine is 0.85! I presume as you say Uno45S you have the Carb model as the Injection Uno is badged 1.0IE or what ever the engine capacity and trim level is.

Spark Plugs for 1.0 - 1.1 Fire Engines (Without Catalyst) Shop4Part Number: S4P923 at £1.71 + VAT each.

Hope this helps.

Re: HELP! Uno 45s firebox owner on steep learning curve.

gems said:

Uno put in for MOT last week, failed on emissions & rear brakes. Garage sorted & gave all clear, now less than a week later:
1.the engine cuts out when slowing for lights/slow rush hr traffic
2.electrics (indicators) fail go off & come back on again of own accord
3.fuel gauge has works intermittantly
4. fuel thirst-nearly 3/4 tank in less than 200 miles
5.windscreen wash doesn't 'whhrr' at all and can cause fuel economy gauge pointer (when it doeswork) to slam over to the left when wiper-wash toggle pulled.

Click to expand...

Welcome to the Forum Gems!

Firstly, whatever the garage did to your car has obviously caused some or all of these faults. As has been suggested, take it back and see if they can put it right as in theory they are liable.

Engine stalling. Check the vacuum advance unit on the the distributor. 9 times out of 10 these fail and cause these symptoms. Also, if it isn't working then the timing will be out (plus can't be set properly) and this can cause excessive fuel consumption.

You say if failed it's MOT on emissions, so I assume that the garage made some 'adjustments' to the carburetor to make it pass. They could have possibly lowered the idle speed too low, or most probably adjusted the mixture too weak. Both of these can cause stalling. More so with the lights on and an electrical load on the cars circuits.

Morten is right with regards to the electrics. It sounds almost certainly like an earth wire has been disturbed. Electrics going weird, and particularly switches making gauges do strange things points to an earth problem. What is happening is that when you operate the switch, that circuit can't earth itself on the earth wire so goes down the next available route. Sounds like yours is going through the economy gauge.

From memory I think there are at least two earth blocks under the dashboard of the Uno (mk1). One is just above the fuse box in the passenger footwell, and the other (I think, not sure) is on the drivers side up behind the dashboard. They look like a sort of big silcone chip upside down with two rows of prongs/ spade connectors. These should have a load of black wires attached by female spade connectors. Make sure everything is connnected!

Also check obvious things like the battery cables and the engine earth strap.

The econometer is simply a vacuum gauge that measures pressure in the inlet manifold. I don't know if they fitted them to the mk2 Unos, so is your Uno a mk1 Gems? I think they were only fitted to 'S' models. Louies Bianca Turbo lookalike probably had one as standard (the Bianca was a special edition 45S/60S), but his car now has the turbo dashboard in it's place!

The econometer dashboard gauge itself is electronic, and the sender unit is in the engine bay either bolted to the passenger side suspension turret next to the coil, or somewhere in the centre of the bulkhead/ firewall. This is a little unit with two wires connected to it, AND a vacuum pipe. The vacuum is taken off from the brake servo hose, which runs to the inlet manifold. A 'T' piece is connected to this hose and a little pipe is then run to the econometer sender unit. I've attached a picture to show the location of the sender unit on my car.

As your gauge is behaving strange with the rest of the electrics it's far better to investigate the electrical/ earth fault first rather than diagnosing individual gauges. You'll probably find there is nothing wrong with the gauges or the rest of the electrics once you get the earth problem sorted!

Best of luck with your Uno, and let the board know how you get on. If you need more help/ advice please ask!

Chas

Chas- thats fantastic , you're er incredible . Will certainly let you know what happens and will print off all your invaluable advice. You are all top! gems

I had all these problems with my uno. the not idling problem was intermittent and was caused by the lack of a warm air feed from the manifold to the air box, and a perished vacuum advance unit. replacing these sorted it out and it ran well after that. (It was particularly bad in cold/damp weather but fine when warm).

I may be unlucky but whenever i have had a rusty spark plug its been a head gasket problem, but there would be a number of other things going wrong if it was that!

I had to regularly clean the electrical connection blocks on my car to keep the electrics working. I had a carb Mk1 uno 45 and one terminal was at the right of engine bay somewhere down near the cooling fan as i can remember? It has about 6 spade clip connecters on it. They go really rusty and gave problems on mine. There is also another one on the left of the engine bay as you look at it attached to the right front wing. There may be more but cleaning these seemed to fix most electrical problems on my car including headlights and the cooling fan. The electrics on my car were so bad i could go over a speed bump and all the lights would go out, go over another bump and they would all come back on again!

An alternative to the idling problem is adjusting your driving style and using the handbrake and being quick with your feet....I wouldn't recommend it though!

Phil

Hi Gems,

Ditto to all the above - some great advice there on electrics from Morten and Chas...

Re: idling, I've found with the 45 FIRE that the carburettor provides a mixture that's too weak for reliable idling, even if the mixture screw is turned all the way in. This is probably why you're having to use the choke, which is probably throwing the emissions and fuel economy out the window. As Louie says, things will be even worse if there's a leak at the vacuum advance unit (very common) because this will be allowing in extra air, and also upsetting the economy gauge - so quite possibly a link there!

There is a brass jet for the idling mixture, in the top of the carburettor, on the left side as you face the engine. You can get to it easily with the airbox removed. I've replaced this '45' jet with a '50' or even a '70', which you get from the carburettors fitted to older Uno 70 models. The result was that the mixture adjustment screw started to have much more of an effect, and the idle became smooth and steady.

So, once you have finished the current business with your garage, I suggest you find somewhere that has a collection of older FIAT carburettors, and just run it past them that your carburettor may require cleaning/rejetting... it's made a huge difference a couple of times for me. You can of course sort it out yourself: a can of carburettor cleaner, a '50' or '70' Weber idle jet, and some compressed air to blow the carburettor out once you have the top off.

Hope you get your Uno running smoothly again soon!

-Alex

How does one calibrate the econometer?
I imagine it is E-Z to attach a vacuum gauge to the hose leading to the sender unit (I have one - bought at the local flea market for less than 1 Euro ), but I am not aware of any table showing the relation between the vacuum and the position of the needle on the instrument panel.
I have noticed the adjustment screw on the sender unit, but I do not want to play with the gizmo without any references.
Yes, the simplest way to adjust the thing would be:
idling = lowest, full throttle with no gear = highest, but...

(CZ)enda said:

How does one calibrate the econometer?
I imagine it is E-Z to attach a vacuum gauge to the hose leading to the sender unit (I have one - bought at the local flea market for less than 1 Euro ), but I am not aware of any table showing the relation between the vacuum and the position of the needle on the instrument panel.
I have noticed the adjustment screw on the sender unit, but I do not want to play with the gizmo without any references.
Yes, the simplest way to adjust the thing would be:
idling = lowest, full throttle with no gear = highest, but...

Click to expand...

That pretty much is all you need to do! The gauge is only really meant to be a guide rather than an accurate measurement. At tickover the needle should point low down in the green sector, at moderate openings it should be somewhere in the yellow, and large throttle openings (engine under load i.e. top gear accelerating hard) it should go into the red.

That's all it's supposed to do!

The only adjustment I can think of is to check that the needle goes to the end of the red sector when accelerating hard. Once it is set like that, then all should be fine.

Chas

Thanx - then I will adjust it as suggested.