Technical Electrical/fuel issue

[2cinqgal]

Hi there
Bought a Fiat Uno 1993 1.1 for my daughter 2 years ago to drive after passing test.

Only 2 owners (one a lady driver for 30 years) and 19k.
Practically immaculate.
We've only put a couple of hundred on the clock.
It was running great, but developed a fault last year which I would describe as either pulling poop up off the bottom of the tank, or maybe basic level electrical: spark plugs or HT leads?

The fault is that it loses power on acceleration on a slope. It will still pull but at reduced speed as it hits a flat spot and feels like there's an interruption in fuel or electrical supply.
20mph is the top available speed at that point.
Once you are back on the flat it rectifies itself and the power and speed pick back up again to acceptable (within the speed limit) levels.

Sometimes on starting it can require skilfully throttle fettling - we do live on a slope.
I have been told by various mechanics that it's impossible to get hold of an electrical pack now.

Any thoughts welcome

 

[bugsymike]

Hi there
Bought a Fiat Uno 1993 1.1 for my daughter 2 years ago to drive after passing test.

Only 2 owners (one a lady driver for 30 years) and 19k.
Practically immaculate.
We've only put a couple of hundred on the clock.
It was running great, but developed a fault last year which I would describe as either pulling poop up off the bottom of the tank, or maybe basic level electrical: spark plugs or HT leads?

The fault is that it loses power on acceleration on a slope. It will still pull but at reduced speed as it hits a flat spot and feels like there's an interruption in fuel or electrical supply.
20mph is the top available speed at that point.
Once you are back on the flat it rectifies itself and the power and speed pick back up again to acceptable (within the speed limit) levels.

Sometimes on starting it can require skilfully throttle fettling - we do live on a slope.
I have been told by various mechanics that it's impossible to get hold of an electrical pack now.

Any thoughts welcome

Does it feel like it just runs out of steam then maybe fuel or even a blocked breather to the fuel tank (see if same with fuel cap off) has any fuel filter been changed, if only the one in the tank that gauze can get blocked over the years, remember to only use E 5 fuel not E 10.
If it misfires when slowing down then more likely ignition/ plugs/leads / distributor cap.
generally if electronic ignition it will die totally, but even then some parts may be available. Just because a mechanic cannot obtain from local motor factors does not mean impossible.

 

[2cinqgal]

Does it feel like it just runs out of steam then maybe fuel or even a blocked breather to the fuel tank (see if same with fuel cap off) has any fuel filter been changed, if only the one in the tank that gauze can get blocked over the years, remember to only use E 5 fuel not E 10.
If it misfires when slowing down then more likely ignition/ plugs/leads / distributor cap.
generally if electronic ignition it will die totally, but even then some parts may be available. Just because a mechanic cannot obtain from local motor factors does not mean impossible.

As far as I know its had little done to it - it's the classic one lady owner stored in a garage, until last owner who didn't have it long - it was a covid necessity car after losing company car.
I've had to use it for last 48 hrs as my runaround due to deer damage on my daily motor.

It occurred to me last night as it was again struggling up the hill, then rectifying on the flat that it's probably running on 3 cylinders. It's always the incline that shows the fault, although it can be temperamental on starting I guess depending on the cylinder positions of firing?

Once it's on the open road it cruises at 50mph no issue so long as momentum is up.
No sounds of misfiring then.

Fault feels like a tiny bit of lack of compression on a hill, it does lose minimal power, however you can keep it steady without losing more by keeping the revs minimal which means (I think?) it's operating rough when fuel demand starts to peak at top end of 20 -30,000rpm.

But if you just give it a bit too much throttle it goes what my old man used to call 'kangaroo petrol'.
Then the firing sequence feels like it's getting unable to keep up with itself and is almost going to fast for itself and starting to misfire until you slack off and only give minimal throttle by which time that bit of acceleration power uphill is lost.
If that makes any sense!

 

[2cinqgal]

Could it be as simple as spark plugs?
And if you replace them do you need to do HT leads too?

It did occur to me that it could be the points?
But that's a job I haven't tackled for 30 years!

 

[2cinqgal]

I took it to a recommended mechanic 2 days ago - recommended by word of mouth. Good and bad reviews on Google.

I haven't managed to find anyone else that will tackle it locally including a classics garage that the 2nd owner recommended (probs not valuable enough as a job) and an alleged Fiat specialist.

It's booked in for next week for a look see, but I found the mechanic's attitude pretty off.
It actually wouldn't start when I set to leave.
I asked if he'd give me a push.
He said no.
It is a heatwave - I'll give him that.

It's also booked in for an MoT elsewhere next week. He told me it would probably fail on emissions.
It didn't for last 2 I have put it through.

Anyway feel pretty annoyed as I don't do my own mechanics anymore, but I'm not an idiot.
However I am female....goes with the territory.
Mechanics over the years have had to get used to the fact I do know stuff and are 85% OK with my expression of knowledge.

It would give me great pleasure to actually fix this myself and not have to use this guy if my ex's haven't completely lunched all my tools out.

However he did say he thought have probably just about had the right leads (HT ?) for this year.

As it failed to catch on ignition he said through the window "That's probably that fault"
"Yes it is" I replied.
I then proceeded to get it going and fire the cycle into some regularity in front of him and drive off.

 

[bugsymike]

Sorry the bit at #2 should say under load as in pulling up hill and not" If it misfires when slowing down" so I must have got too much sun.
If you feel it is misfiring under load as though one plug lead was off, then I would change the spark plugs and also at least test the HT leads. If you have a multimeter and set it to Ohms, put one lead to each end of each lead you are testing, what you are looking for is "continuity" if no reading when you make a connection then it points to the lead being broken internally and needing replacing. It was very common when suppressed leads first came out.
Re points, if your mechanic was saying electrical pack impossible to get, that would indicate he thought it didn't have points.
According to my books it is electronic ignition, there are different versions so maybe a photo of your system including spark plug/leads distributor and coils or coil pack to identify will help. Incidentally from what I see online parts are available.
I would start with a new set of spark plugs and test /replace HT leads as required.
If unsure ask, I or others can help.
None of it is "rocket science" , it just seems like modern garages just want to plug a computer in and have it tell them what to fit, hence the term "fitters" and not what I would like to think I am, a Motor Engineer, albeit an old retired one.

 

[bugsymike]

Re emissions failing Mot that the mechanic said it is probably due to the misfire, so ideally once misfire fixed and a good blast down the road to clear the muck out so it is running smoothly then that should be fine.
As I say please ask if unsure.