2006 1.4 8v Sport Active

Mileage 72,000

Hi everyone! Im new to this forum.. I joined on the off chance of finally getting the bottom of an on going issue with my GP. Im hoping ( praying! ) that somebody around here has had the same problem and can tell me a quick solution and this can all go away thanks in advance.

I've had the car around 12 months now and pretty much from day one the car has been playing up. The car starts fine, apart from a message appearing intermittently on the dash saying " excessive coolant temperature", even when cold. Im not sure if this is separate issue though. However once the car has got to full operating temperature it begins to miss behave a little.
The main issue is approaching junctions/ lights/ roundabouts. As I drop the clutch and start to brake the rev counter drops like a stone all the way to 2/300 rpm. Sometimes it will bounce back up to 1500 rpm and then settle again around 1000 rpm, but sometimes it will go right off the scale and die. Most of the time I won't notice it untill I go to set off again, which gets quite embaressing in a line of traffic!
Also the power delivery is quite lumpy/ jerky and if I try to hold the revs at a fast idle the needle will fluctuate up and down ( moving or stationary ) making smooth driving impossible!
Now the problem seems to have started to develop, as the car has also started to bogg under hard acceleration as if its running out of fuel. But this has only happened a handful of times.
I have noticed that when the revs start to drop when slowing down the speed of the heater fans will also slow slightly and my headlights will dim a little.. so im not sure if this is comman for a fiat or if this all could be a battery/ alternator/ servo issue. Or could it all be a fueling/ breathing or electrical/ sensor issue?

So what iv tried so far....

First thing I did was look into the induction system and clean out all the breather pipes, checking for splits or cracks. Found a bit of gunge but I believe this is normal? Nothing else. While I had the airbox off I checked and cleaned the throttle body finding no obvious problems.
Also replaced air filter and oil. None of this made a difference.

Next I replaced all the spark plugs, even though there was no misfire I thought it was worth a try.... but nothing.

Next I replaced the ABS/speed sensors as I picked up a road speed sensor fault code using an OBD reader. Cleared faults after fitting but still no joy....

Next I thought id bite the bullet and take the car to our fiat dealer here in sheffield.... however after handing over £85 for my diagnosis I was told that no faults were found found and everything was good! After explaining the issue in a little more detail to the technicians, I was simply told that as there were no faults showing on their computer and that it could be anything, all they could do was start changing parts... so I left none the wiser and £85 lighter!

By this point i'd started getting the odd bogging syptoms. And as it felt asif the car was being starved of fuel I though I'd replace the fuel filter... now im still not sure if this is right but I was told by our parts supplier that there is no fuel filter on my car? Well If there is I cant find it! Haha
Anyway I assumed there was some sort of filter built in to the pump, and tracked down a replacement ( used ) pump. Fitted it but still exactly the same.....

Finally I had the check engine light appear while bogging my way up a hill on the way to work. While it only stayed on for a few hours of driving I managed to get the code from it. I forget the exact code now but It was related to manifold absolute pressure/ MAP. So I went and started to investigate the wiring around the manifold sensors but everything looked good. So decided to change the map senor. However after finding what seemed like two map sensors I was unsure which one to go for so I just changed both... but as you can probably guess, nothing changed! Still runs like @#$!!!

Im all out of ideas now and getting deperate for a solution, is there something obvious that im missing here? Am I a complete idiot? is this a common punto kwirk? I dont know.. where to go next?..
Its a shame because I actually like the car and I dont want to end up selling it on to some other poor soul knowing the misery they it will cause them. But Im wondering if thats my only option now?
Anyway I apologise for the essay but I felt it was important to give as much info as possible.. please help me

Cheers Ross!

have you got more info? if its running poorly id check all your filters, check your throttle body, your maf might be on it way out hows your fuel consumption? could your fuel filter be blocked? fuel lines blocked?

Yeh sorry mate info above! Clicked post by accident..

Fuel consumption averaging around 33/34

Hi Ross,
and welcome,
( nice trials bike in sig.)

I'm new to the GP's as my car is essentially NEW ,
but I've read the Coolant temp thing before,
I suspect it's either the old water ( corrosion) in fusebox chestnut

or a bad earth / connection,

the reason it's not storing fault being they are not ACTUALLY there
( as a Fault),

look through the stickys at head of GP section,
good list of common issues there,

then I'm sure one of the "regulars" can add to your knowledge of what causes what

have fun,
Charlie

first thing i would do is go back a step.....

Reclean the throttle body

then try a throttle relearn have a good read of this thread

https://www.fiatforum.com/grande-punto/262685-1-2-wont-idle.html?p=2697299

Thanks guys I'll have a look at the throttle body again and try the throttle relearn. I did try "relearning" last time but I found a few different procedures for it so I probably got it wrong. Ill check the earths aswell while im at it and let you know how I get on.

Thanks

So just cleaned the throttle body again with some carb cleaner and followed the relearn procedure, but had no luck.. had a good check around the wiring aswell but I couldn't find anything abvious a miss.. any other ideas guys?

Thanks Ross

I had a similar problem until one day the car refused to start, it didnt make a sound when turning the key.

Anyway i got it towed to a garage and was told the alternator had seized and needed replacing, this cost me £475 for the whole process of towing, diagnostics, labour and a new alternator. I have not had this problem since.