Technical Very poor fuel consumption, Fiat panda 1.1 active, where to look first

[koalar]

video at post 76 in the link above

Is a working car

 

[Revilo]

 

[Revilo]

Held at idle for 100 seconds, both 02 sensors log

 

[Revilo]

After 100 seconds at idle 100 seconds held at 1800 rpm

 

[Revilo]

Had a nightmare with the plugs, lead 1 (left) snapped, 3 didn't budge at all, will probably snap aswell,

2 and 4 came off ok, will get a new set on order,

Photo of plugs 1,2 and 4,

Will have another go at number 3

 

[Revilo]

Due to the difficulties with the plugs and leads, I've orderred a new set, plug gap looked excessive, estimate 2mm,

So I've orderred new plugs and leads, for peace of mind.

 

[koalar]

Due to the difficulties with the plugs and leads, I've orderred a new set, plug gap looked excessive, estimate 2mm,

So I've orderred new plugs and leads, for peace of mind.

Gap should be around 1mm give or take

Depending on brand .8 mm and 1.2 mm

The car normally start to misfire at 2 mm takes well over 50 000 miles to get to this

 

[The Panda Nut]

Check the throttle body is also clean. This may require special care on the 1.1 if the MAF sensor is buuilt in.
Someone mentioned the exhaust, while unlikely internal baffle failures could possible cause issues.
I would also clean the crank case breather pipes and consider changing the flame resistor in the main breathrer.
Are you using E5 or E10 petrol? Personally, I would steer away from E10.
You could try a fuel system cleaner additive and see if this makes any improvement.

 

[koalar]

Not seen yellow plugs for 20 years

Some good news none show any sign of oil burning

The state of the plug tops look like they have been in there for a decade

Not the original plugs though


Milage and year of car

 

[koalar]

Barometric reading doesn’t look right

Might be different to mine as mine 1.2 doesn’t have an idle control valve

But at idle I would still expect some vacuum and read less than atmospheric

 

[koalar]

When putting the plugs back

Always wind them in a fair bit by hand first aluminium heads are easily cross threaded

 

[koalar]

The post CAT O2 should be fairy flat at a constant 2K revs

Certainly isn’t running correctly

I see the car set in software is a 141 panda not a 169

 

[Revilo]

The post CAT O2 should be fairy flat at a constant 2K revs

Certainly isn’t running correctly

I see the car set in software is a 141 panda not a 169

That could well have been me, mis selecting it on the system, it didn't auto find it, so I had to go through the list,

Plus I'm not familiar with the snap on software

The car was relatively warm allready, but had stood for a bit before plugging in,

Maybe cat had gone cold?

But yes I do agree it doesn't look right, from my minimal knowledge on this.

Also car is a 2006, and has around 76,000 miles.

 

[Revilo]

Check the throttle body is also clean. This may require special care on the 1.1 if the MAF sensor is buuilt in.
Someone mentioned the exhaust, while unlikely internal baffle failures could possible cause issues.
I would also clean the crank case breather pipes and consider changing the flame resistor in the main breathrer.
Are you using E5 or E10 petrol? Personally, I would steer away from E10.
You could try a fuel system cleaner additive and see if this makes any improvement.

Throttle body did look a bit mucky, generally oily, I didn't see a maf, although I don't know where it is.

Are these cars not rated for E10,

I haven't had a petrol car in 10 years, diesels my preference,

Will it do it harm running on e10

 

[koalar]

Throttle body did look a bit mucky, generally oily, I didn't see a maf, although I don't know where it is.

Some oily is to be expected on a car of this age

Not normally a problem unless it’s a white water oil mix

If excessive it can get onto the MAP sensor bolted onto the inlet manifold left side. A drop on the sensor will mess the fuelling. Often a misfire at idle and hesitation on acceleration that clears up on a faster run

Are these cars not rated for E10,

Yes

I haven't had a petrol car in 10 years, diesels my preference,

Will it do it harm running on e10

Mine runs fine on E10 the engine was designed to run on a lower octane so 95 should be fine

No idea why some people struggle with theirs and others don’t.

 

[DaveMcT]

It's well worth buying a good quality spark plug socket especially for engines with deep set plugs. The more solid tube puts a more direct force where it's needed. Mine cost me £25 which was daft for a motorbike with shallow set plugs, BUT its been excellent ever since & well worth the extra.

 

[DaveMcT]

Throttle body did look a bit mucky, generally oily, I didn't see a maf, although I don't know where it is.

Are these cars not rated for E10,

I haven't had a petrol car in 10 years, diesels my preference,

Will it do it harm running on e10

I run both of our 2007 petrol Pandas on posh petrol which is E5. E10 is fine. However, I avoid 95 RON because they run so much better on 97 or above. These engines power and consumption spec are done with 97 RON fuel. They will run fine on cheaper, but they get ever more sluggish - as will any engine. The ECU protects from knock damage by retarding the ignition timing. Cheap fuels have the same energy content but the engines throw more heat down the exhaust pipe so you get less of everything at the wheels.

Costs? I reckon British posh petrol costs about the same per mile as vanilla 95 RON so it seems a no brainer to use the better stuff. The car is nicer to drive for little to no additional costs.

As an aside, my BMW R1200GS motorbike hated 95 RON it would stall and struggle feeling like the brakes were binding. Use 97 or better and it just took off. Maybe the ECU had a simplistic advance/retard (one or the other) but the handbook did say it would run on 87 - with "reduced performance". I'll bet the exhaust headers were glowing red on that stuff.

 

[koalar]

This may require special care on the 1.1 if the MAF sensor is buuilt in.

no MAF on any panda petrol engines

 

[eeeno]

Well this is what happens if one doesn't change the spark plugs. A catalyst and O2 sensor failure is only a consequence but if caught early, it should be fine with new spark plugs.

Just take a look at the service history and compare to the schedule. New filters wouldn't hurt either. No need to change sensors just yet.

Believe it or not, I had bought a Fiat with poor spark plugs too. The previous owner was pretty clueless. The car was running a little too rich due to poor sparks and then ECU started to lean the mixture. It was all well within the boundaries, passed the emissions too but with borderline HC. No high fuel consumption either. Car was just powerless.

 

[DaveMcT]

Ours went the other way. No obvious misfire but there was enough to put unused oxygen down the exhaust and that had the ECU running it rich.