Technical Damsel in distress... and the car too!

[tree183]

Hi!

I have a T reg 1.2 16v Punto Cabriolet. I think it's misfiring, can anyone help?

At first it was juddering and felt like it was going to stall, once I started moving it felt like there was no power, then suddenly something would kick in and I'd have power again for a few seconds.
I repaired a hole in the Air Intake duct and this helped quite a lot! Unfortunately the intermittent power gain was still there.
Sadly my car failed it's MOT on emissions and the well-known garage said they could replace the Catalytic Convertor for £300-odd. I said I thought it just needed new spark-leads. The mechanic scoffed at that so I declined and took it to a friendlier garage (I don't know why I didn't use them in the first place really!)

Since then they changed the spark plugs, ht leads and checked the coil things. Apparently my valves are ok... and that's it. The only other thing we can think of is the ECU, but there's no warning light on the dashboard, so I'm hesitant to spend out on that if it might not be the problem.

Sadly I'm selling my Punto, it's been great to me over the years but I'm looking for a car with a bigger boot.
I want to sell it with MOT, I think it's worth something, but without MOT I wont make back the money I spent trying to fix it.

I only have another week before I need to pay for a new MOT instead of a retest, so any help is greatly appreciated! If I can answer any questions, let me know.


All the best,
Tree

 

[fingers99]

I'd get the codes read -- shouldn't cost more than 30 quid -- post anything here. Ask your friendly garage to check out the lambda sensor and connections.

 

[tree183]

Thanks fingers, I'll do that! You're wonderful!

 

[DaveMcT]

Poor emissions can mean the catalyst is clogged or just cold. When the lambda is fixed (or shown to be ok) take it for a long motorway drive and see if the emissions improve.

 

[tinytim]

agree with whiteSei:
very unlikely to be irreversible damage to the cat converter; an "italian tune-up" is required; do this and then remove the air filter prior to the test; replace afterwards....

 

[s and b]

could be something as simple as a clogged airfilter,ive seen these on cars that have got damp and would cause all kinds of problems
not keen on garages that throw parts at cars then suck through teeth and say ecu,it means they are clueless and hopeless
i would dearly love to find the ecu mountain (probably next to the wine and butter mountains) and be able to resell a lot of them to motorists as A1 good

 

[DaveMcT]

For little more than the costs of having the codes read at a garage you can get your own kit. Though you do need a laptop PC.

Search Fiat ECU Scan and all will be clear.

 

[tree183]

Thanks for all the help - will memorise this and have a chat with the boys at the garage... Gotta make it look like I know what I'm talking about!
I'll let you know how it goes!

 

[tree183]

Well, the car wont start now. I'm looking at over £500 for repairs, maybe even nearly £900 to get it through it's MOT. Mechanic offered to buy it off me.
Sad time, but I'm glad she wont be scrapped.

 

[DaveMcT]

Get a 2nd opinion. He has a serious conflict of interest.

 

[ChrisUK]

Sounds very iffy to me.