Technical 2009 Panda jolts and stalls

[oil]

Hi there, this is my first post!

I bought my 2009 Panda 1.1 (40 kw) from my friend (who was the first owner). 73k km odometer.

At first, one day I noticed that the front wipers doesn't work, but then started working without any intervention. One time, they stopped wiping on the highway (in a heavy rain) and I almost crashed. Went to the mechanic, said it was a faulty connection, cleaned the pins and worked fine. This happened again three times, but usually could be resolved with a gentle nudge to the wiper motor. Washer pump works without any issue.

Approximately 2 months ago, I started to notice fluctuations in RPM after driving over bumps or tram tracks - with accelerator or gear shifted, it just jolts (sometimes check engine flashes); without accelerator or when in neutral it usually stalls. After those jolts, the RPM is unusually high (as if I was pressing on the accel pedal). Those issues are frequent, but random and frustrating (got me in a sticky situation few times). Went to another mechanic, said the car is mechanically fine; the issue is most probably electrical and that I should seek a second opinion.

I just tried to wrap the cable bundle with an insulation tape, cleaned the earth and battery pins. Worked for approx. 2 kilometres, then the issues started again. Wipers doesn't work at this time.

Thank you for your thoughts!

 

[oil]

Forgot to mention - OBD reading gave some rubbish nonsense codes, but the mechanic said that the most prominent were accelerator potentiometer and choke valve.

 

[GaryinAmsterdam]

My 2008 Panda just started to jolt and want to stall when either sitting in traffic or even at highway speed. I just had the muffler replaced prior to this, so assumed that was the issue. My mechanics, who I want to trust, think it's the 'engine computer'. They are Dutch so the translation is difficult for them. I think they are saying it's the ignition computer, which is basically an electronic distributor cap. He said it's very common.

They are sending my "computer" offsite to another shop who tests and repairs these. Not sure it's the same thing, but will let you know.

 

[oil]

My 2008 Panda just started to jolt and want to stall when either sitting in traffic or even at highway speed. I just had the muffler replaced prior to this, so assumed that was the issue. My mechanics, who I want to trust, think it's the 'engine computer'. They are Dutch so the translation is difficult for them. I think they are saying it's the ignition computer, which is basically an electronic distributor cap. He said it's very common.

They are sending my "computer" offsite to another shop who tests and repairs these. Not sure it's the same thing, but will let you know.

Thanks! Will keep you up to speed too if smth changes

 

[koalar]

Cable throttle or fly by wire

 

[koalar]

Forgot to mention - OBD reading gave some rubbish nonsense codes, but the mechanic said that the most prominent were accelerator potentiometer and choke valve.

What were the codes

accelerator pedal potentiometer, or throttle body potentiometer is strongly related to

After those jolts, the RPM is unusually high (as if I was pressing on the accel pedal).

 

[oil]

Cable throttle or fly by wire

Not too sure (I'm not a big expert), but I think it's electric throttle

 

[oil]

What were the codes

accelerator pedal potentiometer, or throttle body potentiometer is strongly related to

Unfortunately I no longer have that OBD report, but if I recall correctly, it was accel pedal

 

[koalar]

Not too sure (I'm not a big expert), but I think it's electric throttle

If you can take the air box off and post a picture,but makes a big difference to how we go about the issue

 

[oil]

If you can take the air box off and post a picture,but makes a big difference to how we go about the issue

okay, will do after work. thank you!

 

[koalar]

Fly by wire

Cable

 

[DTanner]

@oil when you say that the car jolts as you move over bumps it makes me think of harnessing, connectors or the earth strap, i.e., things that might move and cause a change in sensor data that causes a jolt.

I recommend checking two things, both relatively easy/quick to do:
1) Wire harnessing and connectors
2) Earth Strap

Wire harnessing and connectors:
You mention insulating the wire harnessing but did you carefully inspect it as you went for any signs of wear or fraying that may have exposed conductors?
This would be good to discount - I would not open the harnessing up, just look for exterior damage.
I would also start the engine and open the bonnet. Then move along the harnessing and wiggle it as you go (including around connectors). The idea is to see if you can stimulate a jolt (like the engine sound changing) to narrow down a area that might be causing an issue. There is loads of harnessing accessible (I would not recommend reaching deeper into the engine).

Earth Strap:
You mention checking the ground pins, but did you check the Earth Strap? It would be useful here to have a basic multimeter and check continuity from the negative battery terminal to the engine block. There is a video on this here:


The Earth Strap location is shown in this video of a Fiat 500 (same for the Panda):


The earth strap on mine looks like this, a braided copper strap:
View attachment 462426

If the earth strap is not conducting well you may see some electrical issues and electrical spikes that could affect sensor readings and cause a jolt.

Anyway, these are pretty straightforward to check so I thought I would mention them as I was not sure if these were fully checked yet. If you need any more info on this let me know. I'm not an expert here so recommend you prioritise gathering information for @koalar.

 

[oil]

If you can take the air box off and post a picture,but makes a big difference to how we go about the issue

Hi, thank you for your help! I didn’t manage to take off the air filter, but I took some photos around it, hope it helps just a bit:

 

[oil]

@oil when you say that the car jolts as you move over bumps it makes me think of harnessing, connectors or the earth strap, i.e., things that might move and cause a change in sensor data that causes a jolt.

I recommend checking two things, both relatively easy/quick to do:
1) Wire harnessing and connectors
2) Earth Strap

Wire harnessing and connectors:
You mention insulating the wire harnessing but did you carefully inspect it as you went for any signs of wear or fraying that may have exposed conductors?
This would be good to discount - I would not open the harnessing up, just look for exterior damage.
I would also start the engine and open the bonnet. Then move along the harnessing and wiggle it as you go (including around connectors). The idea is to see if you can stimulate a jolt (like the engine sound changing) to narrow down a area that might be causing an issue. There is loads of harnessing accessible (I would not recommend reaching deeper into the engine).

Earth Strap:
You mention checking the ground pins, but did you check the Earth Strap? It would be useful here to have a basic multimeter and check continuity from the negative battery terminal to the engine block. There is a video on this here:


The Earth Strap location is shown in this video of a Fiat 500 (same for the Panda):


The earth strap on mine looks like this, a braided copper strap:
View attachment 462426

If the earth strap is not conducting well you may see some electrical issues and electrical spikes that could affect sensor readings and cause a jolt.

Anyway, these are pretty straightforward to check so I thought I would mention them as I was not sure if these were fully checked yet. If you need any more info on this let me know. I'm not an expert here so recommend you prioritise gathering information for @koalar.

Hi, thank you for your reply!
I have inspected the cable bundle leading to the engine compartment fuse/relay box, however I didn’t find any signs of external damage to cables, but I still used the insulation tape (just because I didn’t think having cables in the engine compartment without any protection is a good idea ) I have also disconnected the battery and cleaned the pins + cleaned the earth. I have also inspected the engine compartment and didn’t find any loose cables/connections (but I’m not saying my judgement is 100% correct).

 

[oil]

would also start the engine and open the bonnet. Then move along the harnessing and wiggle it as you go (including around connectors).

Tried that with the bundle leading to the engine fuse box, engine was working properly and didn’t stall

 

[oil]

Hi all,

posting for anybody having similar issue - i went to a repair shop with very good reviews, turns out choke valve sensor was the culprit. I'm having the choke valve replaced. The wipers were a different issue - the motor was oxidised due to rainwater buildup (the drainage is chronically bad in Pandas).

Hope this helps anybody else!

Also thanks to anybody trying to help, much appreciated!

 

[rmjbn1]

The wipers were a different issue - the motor was oxidised due to rainwater buildup (the drainage is chronically bad in Pandas).

Gotta keep those duckbills clear!
I think it should really be in the owners' manual.
The first I knew about them was hearing water sloshing, and found the drains blocked. Now I check them regularly, take them out and wash them once a year.

 

[DaveMcT]

One duckbill in my car literally sits in the hole because I can't get at the job to seat it properly. Does it matter? Not a bit. Poke out the rubbers clean up the area and drop them back in. They are there to let water drain out of the cabin air intake. Fiat have done it that way since the Uno (maybe before).