Technical Punto Jerking

[Tris Harris]

I think I have the same problem as you guys. Ive got a 2002 1.2 8v. I usually get the jerking in 2nd after letting off the gas abit, however I find if you just tickle the clutch, like no more than 1/4 it will stop. Strange

Nathan,

Thats just like mine except i don't like to sit on the bite of the clutch as they are quite prone to failing after 40k miles and mines done 45k im going to try an engine fulsh as the idle is slightly unstable and the car rocks back and forth ever so slightly

 

[oktopod]

I think we should close this toppic and add a new one "How many Puntos on the forum are jerking?" and a sticky sayin this is a common fault.

None of the topics regarding this problem were solved. Try this try that, let's just say "it's like that and just the way it is" (Run DMC)

 

[Superfly]

Ppl seem to find this one ok though.

I'm gonna take the tb apart this weekend and give it a right good clean, and I'm also gonna do the injectors, and also check everything mentioned above, HT's (sure they're ok), Crank Sensor etc. I'll let you know how I get on...

 

[Superfly]

Also, can we presume Freddo's was sorted by what he did, no response either way...

 

[Cinqster355]

Well I hate to say it but I have the same jerkyness in my 2000 V plate 1.28v as well. I have changed plugs, checked HT leads, new clutch (nothing to do with this I know) had the o2 sensor checked out (ok).

I am gonna check the crank sensor is clean and wiring is good but I am getting annoyed and can see me selling the car! Mine to intermittent its not stopping me using the car but you do look foolish trying to maintain a smooth ride in slow traffic! :bang: :bang: :bang:

 

[Tris Harris]

I think we should close this toppic and add a new one "How many Puntos on the forum are jerking?" and a sticky sayin this is a common fault.

Don't Think we can make this a sticky until we find a solution to the problem

 

[freddo]

No, I haven't resolved this problem. I checked the ht leads and they appear to be fine. As for the tdc sensor, I simply haven't had time to look properly yet, all I can say is the area around it seems remarkably clean. I will report back when I look at it this weekend.
Can anyone advise, after checking the sensor is clean and the wiring is sound, apart from replacing the sensor what would be the next logical things to check? At the very least I'd like to narrow down the possibilities before resorting to 'taking it in'.

 

[Superfly]

More than a bump than anything else, as I didn't get much chance to do much with the car, however, i did attack and clean some of the electrical connectors for the ecu and the TDC sensor as much as I could with some WD and a rag, and the car seems to be behaving slightly better, could be entirely imaginary though! It is certainly ok when cold, engine braking as it should in 1st or 2nd. Soon gets warm and mis-behaves though!

Might be able to give it a good going over tonight, or maybe tommorrow if I get chance. Does anyone know if the TDC sensor is optical or magnetic, hard to believe that it's optical but hey, it is a FIAT after all!

 

[Cinqster355]

Mine has settled down again and over the last week it has ran sweet as a nut! I am wondering if the fact the battery was disconnected during the recent clutch change has made the ECU relearn engine parameters? Not sure really but its running fine!

 

[oktopod]

I'm thinking it an air flow sensor, or throttle sensor or how do you call it....Buterrfly we call it

 

[oktopod]

I'm thinking it an air flow sensor, or throttle sensor or how do you call it....Buterrfly we call it

Because erratic idle is a common fault, and this could be the same

 

[punto-60s]

you mite need to change the ignition coil, my punto was jerking alot until i got the part changed. when u put ur foot down u have loss of power and a whole loada jerkin. part only costs abot £10 from a scrappy. 5minz to install

 

[kemp2368]

what were your symptons as mine very jerky with a misfire when i try to floor it,but wont go over 40mph and that takes half hour,me also have changed plugs,air filter,fuel filter,02 sensor.ht leads,but when start car and rev her she seems fine it only happens when you drive it,i think ive only got the timing to check and the coils then im a beaten man

 

[lottie_]

my 2000 1.2l (8v) does the jerking thing at low speeds in 1st and 2nd gear, erratically as previously described on this thread.

i was kind of assuming it was the timing belt, could this be the case?

 

[Fram]

Hi guys,
Yep my 2001 1.2 8v does exactly the same, has had new coils, plugs leads, air filter oil and filter, all in an effort to stop these symptoms and so far no joy.
As this is such a common fault, Fiat must know what it is, I will ring the service department today and ask for there advice, but I assume they will just say bring it in and let us have a look.....
Fram

 

[Superfly]

Certainly not an issue with coils/sparks, mine does not misfire at all, just the odd 'bump' at idle. Not timing either, TDCed it myself, and it would be obvious if it was out, it probably would be undrivable.
Still have yet to do any serious work on it though, but will hopefully get some done tomorrow and/or Sunday, will keep you posted...

 

[Fram]

Hi guys,
Well I just rang the main dealers about this problem and gave them all the symptoms, I told them that I had replaced pretty much everything electrical, plugs, leads, coil packs etc, and asked for there advice, they said they had an idea what it could be and said its an ECU fault (though when pressed they would not tell any more). They said to bring it in and they would run a diagnostic on it for the sum of 37 odd quid. I asked if this would cure the problem and they said possibly, but in any case it would identify it.
Well from reading other posts it appears that this might not be the case or that it might throw up a generic fault code that will not identify the actual fault.
So back to head scratching time, I guess as Having just bought the car and then spent another 50 quid on giving it a proper service I am not quite ready to throw more money at just yet!!
So much for a cheap reliable car to get me to work.
Fram.

Just an idea guys, but if everyone phones there main dealers outlining the problem, then reports back here, we could compare notes and maybe shed a little light on the problem

 

[bkr57]

Me too? do you get the engine management light up as well when accellerating? Seems to have happened since the weather changed in the last few weeks.

 

[volxstu]

Check LAMBDA sensor but there will probably still be problems with your sparks i believe it is a common fault with the punto. Do any of you have after market air filters as this often is a factor when this problem arises. I dont know the cause but i think that the sparks are getting very dirty causing them to fail.

 

[Fram]

Right then chaps,
The plot thickens, if you have these problems with your MK2 1.2 8v:

lumpy tick over,
flat spots when accelerating,
lumpy de acceleration,
No warning lights on dash.

Then according to another main dealer I have just phoned, your car is running perfectly normal!! They said they have seen this over and over again and after running diagnostics and having checked almost everything on the engines, they have come to the conclusion that this is a trait of the 8v engine. They did say that there was a replacement stepper motor that sometimes cures the symptoms, but generally in their experience this is just the way these engines run!!
W.T.F...I am pretty sure that if I bought a new car from the main dealers that ran like this it would be going back sharpish. This tells me that they know about the problem but will not, can not, fix it.
Surely there is something that can be done, because not every 8v runs like this, so whats the difference between my 2001 that runs lumpy and somebody elses that doesn't?
Cheers
Fram.