Technical Help my uno doesn't start when hot?

[punto-paul]

Ive just purchased a 1987 fiat uno 60s with the 1116cc engine, considering it was ment to be my back up car it's not doing very well!! Made it 250 yards and refused to start, got home on the back of a recovery truck..yay!!
Had a look at the car and although the engine starts well from cold, the engine gets up to normal temperature (90c) and the fan cuts in. But once it's hot it won't re-start? The starter motor seems to crank over very slow which kills the battery which was the wrong one as from an escort! So ive replaced the battery with a heavy duty one but to no avail.
The previous owner told me the cambelt has been replaced last year, and he's replaced the plugs. Looked through the previous recipets and seen that the distributor, rotor arm and ignition module have been replaced. So think i can rule that out?
So i replaced the coil, cranks over better but still no joy.

I tried again today whilst the car was up on on ramps, and fan didn't cut in and got to 100c. I turned it off straight away, my dad said from previous experience to change the thermostat and engine temparature switch and fan switch. So il have to do that whatever happens, but don't think this is related to the original problem.

However my colleagues at work said to do a compression test, to see if the engine lacks compression. But wouldn't the engine not run well when cold? another said try cleaning/ replacing the earth straps?

Im not sure what to do..:bang:

Any help would be appreciated!!

 

[Gav F]

it woudlnt be compression if it starts when cold and runs fine.
im sure theres some uno techs that could help out because umm im stumped

 

[Chas Uno]

I agree with your colleagues that said clean the earth straps. These might explain why the engine is slow to crank over when hot (heat causes electrical resistance). I'd also check the ignition timing as it might be slightly out, which again can cause slow cranking though I'm not sure whether this would apply to both hot and cold starting.

I'd also be a little bit sceptical about how well the previous owner changed the cambelt. If it's a tooth out you can get awkward starting and sluggish performance so I'd double check that it was timed correctly. Also double check the other components that have claimed to have been changed as again they may not have been replaced correctly.

As for the fan, you said it did kick in at 90 degrees then it didn't later on and the temperature got up to 100? I have a mk1 70SX that uses the bigger 1301cc version of your engine and it initially had similar fan problems when I first got it. The problem turned out to be a dodgy earth connection, sorted by cleaning the terminals where the fan earth wire connected to the multi pin earth block under the battery tray. It's been fine ever since

Which model of 1116cc Uno do you have? Is it the 60 or 60S model? And any pics? It's always nice to see pics of an old mk1 on the forum

 

[punto-paul]

I used to have a F reg 1.3 fiorino van when i was 16! and the problems on that were down to the belt being 3 teeth out in the end as well as the timing!!
I'l have a look at the earth straps next weekend, and see if that makes any difference. I'll clean up the the fan switch as well and see if that will make it work, so i appreciate all the advice.
I'l get a mechanic to look at the belt and timing, as im not the best when it comes to that.
I know it gona be sumet silly, jus can't wait to get it sorted and actually drive it!
This car im sharing with my brother as a back up car!! this is the 1st uno ive had as ive always had Pandas n mk1 Punto's. It was my brother who always had the mk 1 uno's if im honest!! lol he had the 45 & 45s models both in black?
This one is a E reg 60s model in 5 door flavour! in a nice shade of light metalic green! but thats sadly complemented with various patches of black paint.
Complete with tan/ brown interior, and brown dashboard which is erm nice...
Hope to tidy up the paintwork next year to do it justice, as the car seems to be very solid in the right places. Also get a new radio fitted at somepoint, also some new speakers because there missing!! lol
Ive put some wheel trims on for now, but on the hunt for some decent fiat trims. Although i wouldn't mind some alloys to really set the car off, any suggestions?
Im really happy with the car, and glad we saved it from possible fate of the scrapyard.
I'l try and get some pics on for you once ive got her up and running, hopefully very soon!!

 

[punto5dr]

Just some info i have been told...

I have spoken to the person i bought it from and he has given me info on what was done to the car whilst he owned it. He bought it in 2000, it had a broken cambelt. Upon taking the head off he found one bent valve, this was replaced plus obviously a new head gasket. A new cam belt and water pump as well. The cam belt was not a genuine fiat item. The car started and ran fine for 16k in the following 7 and a half years that he owned it, he kept receipts of any other work needed in that time. I then bought it this year and drove 2000 trouble free miles in it. In that 8 years the car has always taken longer to start when hot but has always started.

 

[alexGS]

Sounds an honest little Uno - with the endearing brown interior.

I think you should check/replace starter motor brushes and clean the starter motor commutator. If the engine is cranking over slowly, that and the earth strap is a likely cause. The starter motor tends to be ignored, but (like the alternator brushes) the starter brushes don't last forever. It's really easy to remove the starter motor on these engines, so it's worth checking over and giving a refurbish. If in doubt, get someone who's familiar with auto electrics to have a look at it while it's in bits. It won't take them long to identify whether it will clean up OK or whether the commutator's worn out/burned out too far.

However, another likely cause is that the ignition timing is over-advanced. The spark plugs fire before the pistons reach the top, so the engine rotation stalls! Make sure vacuum advance unit is working (if not, someone may have over-advanced the ignition to compensate and that will make starting difficult). It's a very common problem for the vacuum advance capsule to spring a leak - do a search here.

Don't lose heart - once you have it running right, it should prove to be pretty dependable. It just needs some TLC to get it ready

As for the radiator fan not running, put 12V across the fan motor direct to make sure the motor runs - it could be corroded and sticking, and in need of a clean/regrease? EDIT: since you mentioned that it ran recently, the suggestion from Chas about the earthing problem is more likely

-Alex

 

[punto-paul]

Cheers for the info on the previous work mate, has helped me cross off some likely culprits!!
Managed to get the correct boot badge!! brand new old fiat stock on ebay for £2.49 inc the postage and packaging get in!
Seen some new old stock genuine lamps/indicators and front wings as well, so want to get those if finances allow!!

Tho i think alex is right about the the starter motor and timing, that makes alot of sense!! And il be checking the earth for corrosion, as well as the vaccum unit. The car has had so little use over the last few years, by the looks of it thats a real possibilty!!
Lets face it england isn't exactly famed for it's weather! lol with a few cosmetics and a good valet the car will be back to it's best!!!
Looks like ive got some work to do sunday, hope it don't snow!!

 

[punto5dr]

Cheers for the info on the previous work mate, has helped me cross off some likely culprits!!
Managed to get the correct boot badge!! brand new old fiat stock on ebay for £2.49 inc the postage and packaging get in!
Seen some new old stock genuine lamps/indicators and front wings as well, so want to get those if finances allow!!

Tho i think alex is right about the the starter motor and timing, that makes alot of sense!! And il be checking the earth for corrosion, as well as the vaccum unit. The car has had so little use over the last few years, by the looks of it thats a real possibilty!!
Lets face it england isn't exactly famed for it's weather! lol with a few cosmetics and a good valet the car will be back to it's best!!!
Looks like ive got some work to do sunday, hope it don't snow!!

No worries matey i like to help when i can. Glad it's going to be of use, if you didn't buy it the car would be square shaped by now

 

[punto-paul]

Cheers it's much appreciated, nice to have people to ask when it all goes wrong!!
I really like the car despite the minior problems i can see it's potential, and know it'l be all sorted soon with a bit of tlc.
Fixed the broken wing mirrior as well ,with a spare one my brother had. And he found the correct headlamp too!! what a bonus!!
Once it's up and running im going to sort out a new Cd player and some speakers, especially as my singing is awfull!! lol
Im hoping to start to collect all the parts to tidy up the bodywork, once the car is back on the road. Basically a rolling restoration really in between doing the Punto and my brothers Cavalier.