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Technical 2014 Fiat 500 1.2 acceleration issues

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Technical 2014 Fiat 500 1.2 acceleration issues

Which of the following applies to you?

  • I have a 2014 delivered 1.2 500/Panda and I'm experiencing this issue

    Votes: 22 46.8%

  • I have a 2014 delivered 1.2 500/Panda and I'm NOT experiencing this issue

    Votes: 6 12.8%

  • I have a 2013 or earlier delivered 1.2 500/Panda and I'm experiencing this issue

    Votes: 11 23.4%

  • I have a 2013 or earlier delivered 1.2 500/Panda and I'm NOT experiencing this issue

    Votes: 8 17.0%
  • Total voters
    47
306maxi said:
So the issue is not a 100% issue
Click to expand...

Certainly looks that way. It also looks like it's not a 0% issue, either.

This could be going the same way as the S/S thread.

In the case of S/S, some cars are fine straight out of the box, some need physical work (part replacement/sensor adjustment), and some are down to user misunderstanding about how to operate the car. Dealers often place all cars with issues into the last category, instead of getting their hands dirty, finding out what's wrong, and fixing it.

I can only imagine how frustrating it must be for those who have a genuine problem with their newly purchased car.

I would still like to know more about the rumoured two stage clutch position sensor.
 
My opinion.... And I must stress this is just an opinion.... The clutch switch is a made up thing. Why would there be a dual stage switch? The clutch really has two positions where you'd want it to be, either in or out. Obviously there is clutch slip and this depends whether you're doing a hillstart on the Hardknott pass or trying to get out of a Tesco car park that has a slight gradient to assist with drainage.

Maybe I'm wrong, but I don't see the point of this supposed dual stage switch therefore I strongly suspect that it's a myth perpetuated by well meaning service people.

I certainly agree with your statements about an acceptance drive, but I wouldn't advise anyone not to order a 1.2 as long as the dealership allows this acceptance drive.
 
306maxi said:
Maybe I'm wrong, but I don't see the point of this supposed dual stage switch therefore I strongly suspect that it's a myth perpetuated by well meaning service people.
Click to expand...

I'm keeping an open mind. But if it does turn out to be a myth, those well meaning service people should be strung up - that kind of misinformation helps no one.

306maxi said:
I certainly agree with your statements about an acceptance drive, but I wouldn't advise anyone not to order a 1.2 as long as the dealership allows this acceptance drive.
Click to expand...

That's exactly where I am on this one right now. The 1.2 is a great engine choice for the 500 and I'd not want to see anyone put off ordering one unnecessarily.

I also wouldn't want someone to take a new car home with issues that, at the present time, the dealerships seem unable to sort out.

An acceptance drive before handover is the sensible compromise.
 
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2010 1.2 500 POP 42k on clock.

I do mostly motorway driving with very few starts, I have being feeling that my POP has been bogging down a bit as I try to pull away from stationary lately.

Have spent most of my time driving gently, max 3000 rpm. Now I'm driving with a bit more enthusiasm just figured car was not used to it & was bogging down but would go away as I continue to drive more enthusiastically.

I might try an Italian tune up or two.

On the other hand, after nearly 4 years, just looking at my 500 still makes me smile.

:):):):):)
 
306maxi said:
I gave the pre 2014 option so that people wouldn't skew the 2014 statistics, it's kind of a nothing vote for pre 2014 people :)
Click to expand...

I appreciate the need to remove noise from survey results.

However, the poor throttle response was first reported on the forum in late 2013. The stats for 2007-2013 contain these cases which skew the results in a way that suggests that the problem has been around for much longer than it actually has. This was my explanation for the anomaly that Cei pointed out, ie "why haven't we heard of this before?"
 
I picked up a new 2014 Panda Easy 1.2 this morning, I've only done a handful of miles, but no issue with acceleration.

Given it isn't every euro6 car affected, perhaps hope exists for a fix for those affected.

It feels different, and driving style will need to change slightly, but prefer this in every aspect so far to my 2010 1.1 Active Eco.
 
So much for David Bliss' supposition that all Euro 6 cars were affected, but you won't apologise I'm sure :)
 
306maxi said:
So much for David Bliss' supposition that all Euro 6 cars were affected, but you won't apologise I'm sure :)
Click to expand...

Slow down, Tiger ;) - we still don't know for sure what's behind all the issues that folks have been having.

But I'd agree the leaky manifold theory fits the facts as they've been reported thus far.

Good news if true, as it should be a simple fix for those experiencing this problem.

Photos of any problem cars with missing bolts would be helpful.
 
A simple bolt missing fix would be such a easy fix for those if this is the root cause ,let`s hope so for those affected ,so they don`t have to go months ,experimenting waiting and hoping for our beloved Fiat company to catch up :idea:
 
jrkitching said:
Slow down, Tiger ;) - we still don't know for sure what's behind all the issues that folks have been having.

But I'd agree the leaky manifold theory fits the facts as they've been reported thus far.

Good news if true, as it should be a simple fix for those experiencing this problem.

Photos of any problem cars with missing bolts would be helpful.
Click to expand...



Tbh when I drove a 14 plate car that was fine I was happy to put my t-shirt over my head and run around shouting gooooooooooooooaaaaaaaaaaaaaalll :)


The signs never pointed towards this being a problem with every new 1.2 8v engines 500/Panda
 
jrkitching said:
Photos of any problem cars with missing bolts would be helpful.
Click to expand...

Really helpful...I'd forgot all about the missing bolt theory that I'd read somewhere...i expect that it'll be (or not as the case maybe!) under the heat protection cover at the front?

 
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I should mention that another colleague at work also has a 14 plate Panda 1.2, no issues with that either. It's his mums but he drives it occasionally and would very happily tell me if anything was wrong with it ;)
 
I've just been reading up on some of these thread about the acceleration issues.

The Mrs 1.2 Panda Lounge (built Feb 14) has this flat spot issue.
The 63 plate 500S loaner (built ??) I have at the moment doesn't.

What I have noticed if you sit with the Panda idling, releasing or drepressing the clutch increases the RPM.

With the 500S, the clutch action has no effect on idle speed.

I know modern cars will often adjust idle when it detects a raising clutch to prevent a stall, my 2.0D Jag did this, but it seems Fiat efforts to do this seem to have caused an issue.

This is just a guess, (as I do drive her 1.2 and seem to drive around the problem) the flat spot - sudden take off appears to be a problem if you input a little too much throttle when raising the clutch.
Raising the clutch without throttle input to get the car rolling, then accelerating doesn't appear produce the same effects.

As I understand it, the throttle bypass would be controlling idle and is being signalled via the clutch switch to open up more when the pedal is raised, so opening the throttle body to allow more air in while the bypass is wide open controlling engine speed may be bogging the engine down due to more air entering that it's fueling for.

That is until the signal to inject more fuel (as the driver has control now and has the pedal down) comes into play, hence the sudden take off as it suddenly gives fuel/air control back to the driver and it's all wide or near wide open as the driver is trying to compensate.

Basically, the car's ECU is trying to control the initial pull away, but driver input is buggering it up!

Now I'm wondering, as the clutch switch is either a closed or open signal (depending on the pedals position) disconnecting it should not produce a DTC, the ECU would just think it's in open (clutch up postion) position and allow the driver control over the fuel/air via the accelerator pedal when pulling away.

This would then stop the ECU- clutch switch adjusting the idle/air/fueling when the clutch pedal is raised and may stop the problem.

If I get the chance before I have to hand back this loaner, I'm going to check what is attached to the clutch pedal and compare it to the Mrs's Panda.
I might have a go, if I can find it at disconnecting whatever clutch switch on her Panda, see if it makes a difference.
 
Last edited:
You might not be far off with this theory. The other night I removed the air filter box to get a better look at these supposedly missing bolts.
When I put it back on I forgot to refit the small hose on the back of the air filter box, which I'm assuming looking at it, is the idle air bypass. The pull off performance was a hell of a lot smoother and the acceleration was significantly better. So much so that I knew something had been disturbed, when I checked found I'd missed the hose off. I've had to re-attach as I wouldn't want to drive with it disconnected, but It did make me check that the spigot on the air filter box wasn't clogged (unfortunately clear so not the problem).
 
306maxi said:
Check for a collapsed hose perhaps? They also crack nicely too
Click to expand...

Hope not its only a couple of months old (panda by the way). Collapsing hose is a thought though.
How low do you think the pressure in the air filter box drops by when you open the throttle? could this be stalling the air flow to the Idle bypass?
 
Right, just been out to the carpark (luckily, the Mrs works at the same place as me, Joy eh!)

The 63 plate 500S loaner idles smoothly, the clutch pedal has no effect on idle, whether up or down.

The 14 plate 1.2 Panda increases the idle somewhere between 200 and 250 rpm with the release of the clutch pedal.

Oddly I can actually hold the clutch pedal halfway up and keep the rpm up from around 750-800 rpm to around 1000 rpm quite easily.

On the 1.2 Panda the ECU via the clutch switch is taking control of air/fueling when the pedal reaches a certain position, then releases it when either fully up or fully down.
 
Goudrons said:
(luckily, the Mrs works at the same place as me, Joy eh!):eek:


On the 1.2 Panda the ECU via the clutch switch is taking control of air/fueling when the pedal reaches a certain position, then releases it when either fully up or fully down.
Click to expand...

:chin:Where do you think its controlling the air input- at the throttle body or at what appears to be a small electric valve at the base of the inlet manifold where the bypass hose fits to?
 
The input comes from the clutch pedal.

That signals the PCM (engine ECU) that the clutch is in a certain position.

The PCM then opens the throttle bypass, and it's also probably adding fuel via the injectors at the same time, though without monitoring the fueling it would be hard to tell.

I guessing clogging the throttle pedal at this time is causing the issue.

Only a theory but if the main TB is opened (is it still cable operated?) and the ECU hasn't yet relinquished fueling control, there won't be enough fuel to air, so it's staved of fuel.

Funny how other manuacturers manage it, like I wrote before, my X Type diesel increased rpm with the clutch, but only in gear, but then again it would have done this with fueling alone, as there isn't a TB on a diesel.
 
Last edited:
Goudrons said:
I've just been reading up on some of these thread about the acceleration issues.

The Mrs 1.2 Panda Lounge (built Feb 14) has this flat spot issue.
The 63 plate 500S loaner (built ??) I have at the moment doesn't.

What I have noticed if you sit with the Panda idling, releasing or drepressing the clutch increases the RPM.

With the 500S, the clutch action has no effect on idle speed.

I know modern cars will often adjust idle when it detects a raising clutch to prevent a stall, my 2.0D Jag did this, but it seems Fiat efforts to do this seem to have caused an issue.

This is just a guess, (as I do drive her 1.2 and seem to drive around the problem) the flat spot - sudden take off appears to be a problem if you input a little too much throttle when raising the clutch.
Raising the clutch without throttle input to get the car rolling, then accelerating doesn't appear produce the same effects.

As I understand it, the throttle bypass would be controlling idle and is being signalled via the clutch switch to open up more when the pedal is raised, so opening the throttle body to allow more air in while the bypass is wide open controlling engine speed may be bogging the engine down due to more air entering that it's fueling for.

That is until the signal to inject more fuel (as the driver has control now and has the pedal down) comes into play, hence the sudden take off as it suddenly gives fuel/air control back to the driver and it's all wide or near wide open as the driver is trying to compensate.

Basically, the car's ECU is trying to control the initial pull away, but driver input is buggering it up!

Now I'm wondering, as the clutch switch is either a closed or open signal (depending on the pedals position) disconnecting it should not produce a DTC, the ECU would just think it's in open (clutch up postion) position and allow the driver control over the fuel/air via the accelerator pedal when pulling away.

This would then stop the ECU- clutch switch adjusting the idle/air/fueling when the clutch pedal is raised and may stop the problem.

If I get the chance before I have to hand back this loaner, I'm going to check what is attached to the clutch pedal and compare it to the Mrs's Panda.
I might have a go, if I can find it at disconnecting whatever clutch switch on her Panda, see if it makes a difference.
Click to expand...

Great post there.

I've been meaning to post about the clutch switch/idle speed as I think it might be related to the problem (if not necessarily the complete cause).

Our old 1.2 500 (59 plate) never used to change its RPM when you dipped and released the clutch. However, our 12 plate 1.2 Panda does do that, and it's exactly how you describe.

The two main changes I have found with the Panda compared to the 500 are as follows:

1. It is much easier to reverse the Panda into a space without applying any throttle; you can just bring the clutch up to the biting point and the car's revs will rise a little bit (as you say around 250rpm). On the 500 you'd have to be very disciplined with clutch control if you didn't want to stall it without applying any throttle.

2. However, the flip side is that if you try to reverse the Panda up a slight incline, it struggles and you really have to give it some welly. I really used to have to work it hard to get it up our drive in our old house, even now it has got 30k on the clock now and has never really improved in this respect. The 500 never had any issues here.

Regarding disconnecting the clutch switch; I can't confirm 100% that it doesn't produce a fault code, but our clutch switch broke off in 2012 and all it did was make gear changing rougher and the car a bit jerky if you tried cruising in gear without applying throttle. See my thread from back then:
https://www.fiatforum.com/panda-iii/309721-faulty-clutch-switch.html
 
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