(T) Solution to Punto 75 mk1 Engine Problem

I have a Punto 75 SX M reg (95)and had the following problems

1) At idle the revs where not stable

2) Could not hold revs at certain rpm

3) Excessice CO emissions

4) A hesitation at 3000rpm and then a sudden surge of power like turbo

Problems 2&3 where found at the recent MOT test,and the tester suggested that was the throttle position sensor, becasue the lambda sensor was OK (the limits 0.98 to 1.03 mine was 1.01)

A friend suggested this site a some of you suggested that could possible the temperature sensor.

I was confused and did not want to pay for fault read test (from 40 to 60 £ per hour)

I decided to call a friend from my origin country specialising in Alfa Romeos and FIAT's.

I told him the symptoms and he categorically said it was the lambda sensor, I replied that was inside the limits and yet insisted that was lambda sensor. He even decided to pay for the sensor if was not the problem.

His own words were "if the revs are not steady and fail in CO emissins and not in HC emmissions then it is lambda sensor... a lot of FIATS have that problem. The problem is caused that the sensor is 'slow' (picking the signal right but not responding accordingly)"

I bought the lambda sensor (original £65, non-original £55, I opted for the orignal) and changed it. The changing is very easy and straightforward, a 22 spanner a screwdriver is all you need.

The problem was solved and passed the MOT.

So if anyone has the same symptoms then it is the lambda sensor even if it reads OK

I decided to share my story in the forum in order to help other Punto owners but I don not imply that this is the solution to all cases

I hope that I gave some help

Hi welcome to the forum:)
Thanks for sharing that with us.

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Please do not Email or PM me asking for support. Post on the forums instead. Your reply may help someone else. Thank you

Wow i got exact same problem recently iwent for an mot and the people were unable to hold my car at 2500 revs they tried for several minutes i was getting annoyed as i thought they were just idiots lol they passed me anyway i wasnt complaining lol. also my revs bounce at idle sometimes, and i get that powerloss atabout 3000rpm some times it stays sometimes it goes and i get sudden bursrt of power. my car is a 2001 sporting but would seem like the lambda sensor for deffinate from what you have said and from what others had said in a previous post i made. cheers for the post

2001 Punto sporting in sprint blue with matching Mr Bump air freshner all together now mmmmmmm

I Had All The Usual Problems Of Juddering Starts, Dodgy Tick Over, Holding Back & The Sudden Surge Of Turbo Power.

Traced It Back To The Lambda Sensor, Situated On The Exhaust Manifold, Between The Engine & The Radiator. Mine Is A Gold Coloured Thing, Looks A Bit Like A Spark Plug.

Anyway, To Magically Cure All Your Problems, Simply Locate The Dreaded Thing, Then Trace The Wire Back To The Plug In Socket, & Unplug The Thing !!

You Will Find That Your Car Runs Absolutley Beutifully Without It!

Ive Been So Happy Since, I Thought I Would Share It With The World.

HI JUST UNPLUG THE LAMBDA SENDOR UNIT IT SHOULD RUN BETTER AND THEN YOU NO IF IT IS THAT

High I may have a similar problem, did you have a issue when cold and as the engine became warm the problem disappeared

I have the exact same problem on my Fiat Punto Active Sport 04 Reg.

When cold, revs go up and down, when stationary then when driving the car jitters, stopping at lights, revs go up and down. This continues untill the car has warmed up. Once warm she is fine.

I was wondering if this is related or a different issue, as she has always had this, but never failed an MOT. I also dont get the boosts of turbo power So i may have a slight different issue.

Original post mentioned testing the lambda sensor
Anyone know how this is done? Or do I just disconnect to check if this is the problem? Guess it won't get an MOT with probe disconnected, but I'd like to check it out before forking out for a new sensor.

Car in this case is a Mk1 1.1 55S.

First of all thanks to everyone who posts on here. I'm mechanically dumb and finding this really helpful.

My wifes Punto ELX 1.28V 52 Reg lost all it's power just a couple of hundred yards onto the motorway on her way home from work a few weeks ago. I got to her about an hour later and it started up just fine. Only occasionally since then has the running of the engine been a bit erratic/ revs bouncing up and down.

This morning she rung just after leaving for work and said it was feeling quite bad again in terms of getting that "kangaroo juice" feeling. I've had similar problems with my Vauxhall Vectra and that was diagnosed as the ECG Valve. However after reading this forum does this problem sound like the Lambda sensor? If so, I think even someone with my zero knowledge could probably do something about it.

Thanks in advance.

PS - She's also recently found it really difficult to find gears - coincidence?

Thanks again.