Northern Auto Tech - ECU and Blue & Me Repairs

Technical Punto Jerking

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Technical Punto Jerking

My car shows jerking and kangarooing in 1st and 2nd gears once in a while. Then I takeout the air filter, and give it a good clean with a vacuum cleaner. Usually the problems disappear then. In my experience, air filter cleaning once in three months is the single most important preventive maintenance required for my car (1242 cc SPI, Uno).
 
Superfly said:
Littlepip, 2004/5 cars have Bosch Motronic, we all have Magnetti-Marelli, it's a no go on the software. In fact, the trouble we're experiencing is probably why FIAT finally went for Bosch. It's also drive by wire, so the tb configuration will be different.

Mine is certainly better behaved when it's cold and in the cooler weather, if it is a common trait of the engine, then a lot of preople may not even notice as they 'power and coast' instead of the correct way of leaving it in gear and utilising engine braking.

I'm guessing its just the evidence of all the oily gunk that builds up in the tb over 7 years, getting into pots, sensors, etc. I've never had engine management flash up, no codes stored in ECU, never mis-fires. The other reason i'm more sure its mechanical is because it doesn't always do it. Like I said, I'm going to give my tb a very intensive clean (no-one has had it in bits yet...) and see if it improves, just not had the time...
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your right there i didnt think about the dates were engines were diferent ecus

but there will certainly be a newer version over 2000

but i still agree with you thereon the oil contamination it's the first thing i checked for on my car

the firs main cause of it is groggled cars that need a thrash

the second is people think these cars take time to fill with oil so take it upon them selves to alter the design of the breather system buy bending the corner of the oil separator plate down

meaning monumental amounts of oil spray up into the tb

so if your buying or own a dodgy punto

remove and clean your breather pipe and flame trap located within the breather pipe

then take out your filler cap and check there is no obvious damage to the plate basically you shouldn't be able to see the bottom of the inside of the head

then just a general look into the tb to see if you think it requires cleaning or not

i always check tappet clearance on servicing peoples cars every 24k miles as per service schedule unlike many others and regularly bend these plates back into shape
 
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hay hay update my original claim stands

change your throttle position sensors all of you

i was reading through a file of service news the other day looking for punto grande rear door locks as it happens

and came across 188 punto bad idling around 2000 rpm jerky set off's and slowing down excetra (not the exact wording by the way)

and it basically give all the information on replacing tp sensors for better ones

witch fiat will now stock

fiat have a tool for removing the old one from the tb but i'm sure a screw driver hammer and much swearing will get it out and the new one is simply pressed in with another tool you could substitute with a hammer and socket of appropriate size

this should sort all your problems

if anyone wants the tool numbers and such i can look it up but they realy aren't necessary as it's just pushed in with a washer with rear facing legs to stop it falling out witch can be easily overcome with some prying and such
 
I just posted this in another thread...

My car "coughs" at idle on every 5-25 seconds, so icv is the issue probably, and it could be the reason for jerking :D

Can you do something with this valve in order to clean in or something, or you gotta buy a new one? What's the price, is it easy to do yourself (looks easy)?
 
oktopod said:
I just posted this in another thread...

My car "coughs" at idle on every 5-25 seconds, so icv is the issue probably, and it could be the reason for jerking :D

Can you do something with this valve in order to clean in or something, or you gotta buy a new one? What's the price, is it easy to do yourself (looks easy)?
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well yours is coughing so possibly old plugs you can try soaking the throttle body in carb cleaner specially down the idle passage then leave over night to evaporate and try in the morning

also if there is an excess of oil in the tb have a look at breather pipes and the oil separator plate

these cause this

excess oil brakes the icv

as for tp sensor that caud be the cause of your jerking as i said there is a service news about them causing jerking and bad idling and a later design has been made available
 
Thanks for that mate(y), Just hope thet they arent mega expensive:(
Cheers
Fram
 
Woah hold up, mine is FIXXED!!! :D

Oh yeah baby, no new parts either!

Not sure if it was one of the following, I still suspected the MAF (mass air flow) sensor, but basically hit 60k on Sat so gave it new oil and air filter today, and also took off the MAF sensor and gave it a damn good clean, first with WD40, the some compressed air to dry it thoroughly, plonked it back in again, car works purrfect! Was actually trying to make it bounce/jerk in the middle of the 'bad' revs and it point blank refused to do it! RESULT!

The MAF sensor is hot wire type, basically it's reference for the density of the air, which it can gauge from the temp as the air flows over it. Lower temps means higher density which means more oxygen, so more fuel has to be put in to keep ratios correct. What I was thinking was that the build up of oily crap on it made it give some funny readings, especially at low airflows...

It's torx bolted onto the right hand side of the tb, underneath the filter box as you look at the engine, and is just a little slightly oblong box with a 4 pin connector in the top of it. Inside is a tube with a thermister in it. Thats it! Mine looked ok but cleaned it anyway, and gently re-centred it in the tube.

I must add that I've had the throttle position sensor cleaned about two weeks ago, so it may be wise to do this/have it done too. If it's just the air filter as philipreji does with his Uno, then do this first, as mine now has a new air filter on and it's behaving...

If anyone wants more info don't hesitate.
 
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Been a while since I added my 2 pence worth, after fitting a new ECU (costly guess) I was still getting this jerking problem, so I booked the car in with a mobile mechanic who did a quick service and found that the plugs leads were arcing, so replaced them, along with new spark plugs, and all seems fine again. Only wish I'd called him first, before wasting monet on an ECU which wasn't needed?!
 
bkr57 said:
Been a while since I added my 2 pence worth, after fitting a new ECU (costly guess) I was still getting this jerking problem, so I booked the car in with a mobile mechanic who did a quick service and found that the plugs leads were arcing, so replaced them, along with new spark plugs, and all seems fine again. Only wish I'd called him first, before wasting monet on an ECU which wasn't needed?!
Click to expand...
Sorry, I myself aint much of a mechanic, but changing ECU before checking plugs?:eek:
 
Superfly said:
Woah hold up, mine is FIXXED!!! :D

Oh yeah baby, no new parts either!

Not sure if it was one of the following, I still suspected the MAF (mass air flow) sensor, but basically hit 60k on Sat so gave it new oil and air filter today, and also took off the MAF sensor and gave it a damn good clean, first with WD40, the some compressed air to dry it thoroughly, plonked it back in again, car works purrfect! Was actually trying to make it bounce/jerk in the middle of the 'bad' revs and it point blank refused to do it! RESULT!

The MAF sensor is hot wire type, basically it's reference for the density of the air, which it can gauge from the temp as the air flows over it. Lower temps means higher density which means more oxygen, so more fuel has to be put in to keep ratios correct. What I was thinking was that the build up of oily crap on it made it give some funny readings, especially at low airflows...

It's torx bolted onto the right hand side of the tb, underneath the filter box as you look at the engine, and is just a little slightly oblong box with a 4 pin connector in the top of it. Inside is a tube with a thermister in it. Thats it! Mine looked ok but cleaned it anyway, and gently re-centred it in the tube.

I must add that I've had the throttle position sensor cleaned about two weeks ago, so it may be wise to do this/have it done too. If it's just the air filter as philipreji does with his Uno, then do this first, as mine now has a new air filter on and it's behaving...

If anyone wants more info don't hesitate.
Click to expand...

waaait ahhh minuite

what punto do you have

on mk2 only the hgt and diesels has a maf sensor

what you just cleaned is the idle control valve

witch is why your problem is gone it was probably sticking

https://www.fiatforum.com/punto-guides/123687-were-everythingis-1-2fire-engine-2000-onwards.html

look here and tell me what you cleaned

ps covering a proper maf sensor with wd40 would destroy it

they are always located upstream of any source of oil or contamination normally close to the filter not in the tb
 
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Ah, think I got me lines crossed, twas the MAP sensor, didn't have my haynes at the time (but I knew it was there from Haynes) and so figured i needed cleaning.
 
that's bolted to the side of the manifold if you clean this with wd you will damage it

and it will have nothing to to do with the jerking

it's not a mechanical device

it's simply a pressure sensor

you have probably damaged it causing a change in fuel mixture meaning your jerking has gone for now anyway

and were back to the main point over exuberant oil breather pipes

last time it took one of these manifolds of there was a mm of crud al across the bottom cos the oil separator plate was bent down open your filer cap and take a picture of the inside from directly a both i want to see something
 
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Ok, i'll post the pic on the other thread you've started. I didn't take my entire tb to bits, left it on the car, just took that off the side. Tb seemed relatively oil and crud free, but there was a little bit at the bottom of the idle valve and the manifold.

Jerking is minimal now, but it still will do it occasionally but not as bad and only for a second or less before it settles. Still get surging and pulling between 1.5k and 1.1k though.

Throttle position sensor was cleaned a few weeks ago but it still may be crock. It's either that, fuelling or ht leads now I reckon...
 
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Having kept abreast of this thread since I started it, I was curious that one or two people suggested changing the air filter could make a difference.

I changed the air filter on mine today and I can't believe the difference, the car drives bettre than it ever has. The symptoms have gone altogether.

The old filter, by the way was really quite dirty - by the look of things it may well have been the original [the car is 3 years old this month].

I get the feeling from this thread there is no one definitive cause of these problems, but changing the air filter must be 'on the list' of possible fixes.
 
freddo said:
Having kept abreast of this thread since I started it, I was curious that one or two people suggested changing the air filter could make a difference.

I changed the air filter on mine today and I can't believe the difference, the car drives bettre than it ever has. The symptoms have gone altogether.

The old filter, by the way was really quite dirty - by the look of things it may well have been the original [the car is 3 years old this month].

I get the feeling from this thread there is no one definitive cause of these problems, but changing the air filter must be 'on the list' of possible fixes.
Click to expand...


fiat say change filter every 3 years anyway it's part of the third service aswell as a coolant change
 
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Superfly said:
Ok, i'll post the pic on the other thread you've started. I didn't take my entire tb to bits, left it on the car, just took that off the side. Tb seemed relatively oil and crud free, but there was a little bit at the bottom of the idle valve and the manifold.

Jerking is minimal now, but it still will do it occasionally but not as bad and only for a second or less before it settles. Still get surging and pulling between 1.5k and 1.1k though.

Throttle position sensor was cleaned a few weeks ago but it still may be crock. It's either that, fuelling or ht leads now I reckon...
Click to expand...

you cant clean a broken or defective throttle position sensor

it's all about wrong resistances along the tracks they simply need replacing

that's like giving a blown up engine a good clean and expecting it to work honestly
 
*bump* :D

my car didn't do this till today...

today i cleaned my map sensor,changed the cam cover gasket and alternator belt

when i done my alternator belt i had to turn the flywheel about a qaurter turn, this is all i can think of

ps,i didnt disconect the battery :p when i done this so maybe faulty reading from tdc sensor
 
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