General Help needed, Car is randomly idling.

[gidi19]

Hi all,

Apologies if this has already been discussed elsewhere. I've tried looking and not found anything that matches my problem.

Fiat 500 L twinturbo 2015 plate.
Car has randomly started idling on start up. Will go away if I give the car some gas, but then will come back with a vengeance once the car reaches temp. I have scanned it with a cheapy scan tool and the error codes that come up are
P0221
P1120
P0121
P0351
P0352

On googling the error codes the P0221 and P0121 are in regards to a throttle position sensor.
And the P0351/P0352 are in regards to ignition coil packs.

Can anyone please point me in the right direction on what I should check/replace next,

In the video I have attached I am not pressing the accelerator, it is doing it by itself.

 

[varesecrazy]

Hi,
what is your history with the car?


Looking for recent work.. Or history of overheating..

On a basic 4 cyl engine, there is a recalibration procedure (1999 punto 1242 fire, as an example)


BUT the Twinair uses totally different kit...

I would look for an air leak 1st



IDEA: get the emissions checked


That will tell a story

Unburnt fuel, or rich / lean generally


Garages used to do that for a tenner


Tell us more

 

[gidi19]

Hi,

Thanks for your response.
Have had the car a few years, normal servicing. Nothing recently done.
Had a go at it today, removed the throttle body and cleaned it out.
Removed the 2 injector coils, looked for any visible defects, marked them and them swapped them around.
Started the car, and no difference.
Car just randomly revving up and down.
Took it for a spin around the block, and this time the car actually stalled.
An oil pressure low message came on the dash.
Drove it home slowly,literally 30 seconds and tried the diagnostic system. No error codes to report.
I'll try take it to a mechanic on Monday but am dreading that its going to cost a fortune to fix.
Ive read about the recalibration on these engines, but does it have to be done via a software procedure ?
I left the car running for 15 minutes, would that not work.
Any suggestions I would be grateful.

 

[AnthonyH]

Hi,

Thanks for your response.
Have had the car a few years, normal servicing. Nothing recently done.
Had a go at it today, removed the throttle body and cleaned it out.
Removed the 2 injector coils, looked for any visible defects, marked them and them swapped them around.
Started the car, and no difference.
Car just randomly revving up and down.
Took it for a spin around the block, and this time the car actually stalled.
An oil pressure low message came on the dash.
Drove it home slowly,literally 30 seconds and tried the diagnostic system. No error codes to report.
I'll try take it to a mechanic on Monday but am dreading that its going to cost a fortune to fix.
Ive read about the recalibration on these engines, but does it have to be done via a software procedure ?
I left the car running for 15 minutes, would that not work.
Any suggestions I would be grateful.

I don't understand what you mean by the term "injector coils"?

Do you mean you swapped ignition coil leads around? If so then the leads can be just fine and the coils themselves still faulty. The car stalling could also indicate an ignition coil failure.



The

 

[varesecrazy]

Fuelling is controlled by the oil on these Motors

Get the oil strainer checked and cleaned, many garages don't check it!

 

[gidi19]

Fuelling is controlled by the oil on these Motors

Get the oil strainer checked and cleaned, many garages don't check it!

Hi,
Can you expand on this, whats an oil strainer?
Can you please explain where It is, and how easy it is to clean.
Ive tried goggling it, and its coming up as an oil filter ?
I want to try the easy fixes before I get mechanic to check on Monday.
Thanks

 

[gidi19]

I don't understand what you mean by the term "injector coils"?

Do you mean you swapped ignition coil leads around? If so then the leads can be just fine and the coils themselves still faulty. The car stalling could also indicate an ignition coil failure.



The

Hi yes,
I meant the ignition coils, not the injectors.

 

[AnthonyH]

You should test the throttle position sensor.

 

[gidi19]

Took the oil strainer out, cleaned it with carb cleaner. Put it back in. Car felt better. Drove without any misfires.
Once warmed to temp the problem came back again.
Its just revving by itself.
Any other things I can try ?
Still no dtc codes

 

[varesecrazy]

Took the oil strainer out, cleaned it with carb cleaner. Put it back in. Car felt better. Drove without any misfires.
Once warmed to temp the problem came back again.
Its just revving by itself.
Any other things I can try ?
Still no dtc codes

How good is your disgnostic kit?

 

[varesecrazy]

Took the oil strainer out, cleaned it with carb cleaner. Put it back in. Car felt better. Drove without any misfires.
Once warmed to temp the problem came back again.
Its just revving by itself.
Any other things I can try ?
Still no dtc codes

Does it put Any warnings on the dash..

Or just run poorly?

 

[gidi19]

Does it put Any warnings on the dash..

Or just run poorly?

No warnings on the dash.
Nothing on obd scanner.
Just runs poorly.

 

[gidi19]

How good is your disgnostic kit?

Cheapy one from Ebay.

 

[varesecrazy]

We bought a panda ta

It has run poorly when half warm for the last 30k

Great from Cold, or restarting Hot

Not got to the bottom of that either..

It doesn't flag errors


My punto TA has had mildly poor idle over this winters COLD temps

I turn it off and restart, it is then perfect

Obviously something resets the fuelling..


Maybe experiment with restarts on yours

 

[varesecrazy]

Cheapy one from Ebay.

Possibly just not seeing errors..
But without a screen message there Is a chance nothing has actually flagged a fault

 

[gidi19]

Im going to try get a better diagnostic tool and see if it flags any error codes.

 

[Mike1alike]

That behavior indicates vacuum leak. I had that on the Punto and it was being caused by faulty IACV (Intake Air Control Valve). A new IACV was the fix. I think your car does not have an IACV, as it has electronic Throttle Body. As you found stored errors related to the throttle position sensor, I'd say that's the place to start. Mind you, could be even faulty wiring, take a look at this video

Although probably the sensor is faulty at yours. You gotta check, find exactly what's wrong an fix it.

The P0351/P0352 are in regards not only to ignition coil packs, but to entire electrical circuit with the coil packs, starting the ECU and ending the spark plugs. It is not to be ignored. Usually they show up when the coil pack is bad, true. Bad coil packs can very easily toast the transistors on ECU and you don't want that, the fix for that is another ECU. So you want to fix it before getting there. If the coil packs are bad, new coil packs are needed. But as I've mentioned, those errors can also be triggered by faulty leads (don't know if you have leads on your car or if the coil packs are straight on top of the spark plugs), faulty spark plugs, faulty wiring. Even improper contact between lead and spark plug (or coil and spark plug) triggers it.