Technical P Reg Punto, need diagnostic readout

[Fpwheel]

I have a P reg Punto failed MOT on high CO emissions and does seem to be running a little rough. Does anyone know of garage in Surrey that has the right diagnostic equipment for this car so I can find out what might have failed?
Many thanks

 

[blu73]

what punto is it?

everything except the 1.6 and the 1.7 diesel can be read with a free bit of software called IAW-Scan2 (google will find), but you need the cables but they are cheap on ebay..

search 'vagcom cable' and 'fiat 3 pin to OBD adaptor' - need one of each of them.

If it is a 1.6 you will need to ring around fiat dealers and specialists and ask if they still have a FiatExaminer or not. I have no idea about the 1.7D punto ecu.

 

[Fpwheel]

Hi Thanks. It is the 1108cc petrol. Ringing around but so far not much luck. If all else fails will try it myself as you suggest. Was just hoping someone knew who in Surrey is likely to have this. Main Fiat dealer has not and is not interested as "old" car!

 

[fingers99]

High CO is likely to be leads, plugs, coil packs. Possibly a knackered lambda or even cat.

Really need more info on the "rough running".

 

[Fpwheel]

Thanks really appreciate. Drives fine and sounds ok when revved but idles lumpy and smells "fumey"/rich. Without a diagnostic steer I am reluctant to start changing items on the off chance I may hit lucky but will check those obvious things like plugs you mentioned that I can.

 

[blu73]

have you had the engine management light come on?? If not the ecu will probably not tell you much really.

Anyhow, if you wish to read the codes then it will more than likely be cheaper to buy the cables and download that software than any garage will charge to read the codes for you unless you are getting mates rates.

When was this car last serviced?

 

[Fpwheel]

No warning lights no. All working fine apart from lumpy idling and bad CO, %vol 6.891 against MOT requirement of 3.5? HC reading of 1057 against requirement of 1200 so passed on HCs
Not serviced for some time, so will check some of the simple things and thanks for the advice and pointers to a DIY read out.

 

[Fpwheel]

An update on this and if anyone has any ideas?
Took out the old plugs, worn but ok colour expect one farthest on left (when looking into the bonnet) which was pretty sooty.
Replaced all plugs and also HT leads. Also now replaced lamda sensor.

Engine still idling and running badly and that cylinder really is not firing. There is definitely a spark as seen with plug out (and when putting lead down onto fitted plug large sparking noises until it fits, so for sure HT getting there). No real difference in lumpy idling/running when the HT lead removed so sure that cylinder not working! Plug black when taken out. Have checked spark gap.

Any ideas? HT getting there but not firing? Valves? Not proper mixture getting to just that one?
Any thoughts welcomed on what easy tests I could do to identify the source of the problem?

Thanks

 

[fingers99]

Swap the coil packs over. Does the misfiring cylinder change?

Can't be mixture (as such) as you've only got one injector.

 

[blu73]

:yeahthat:

 

[varesecrazy]

sounds like a mechanical fault;

on Head gasket / bore seal ,
effecting that 1 cylinder.

compression test wet + dry should rule it in / out,

if that looks good / balanced = worth checking valve timing too,

charlie

 

[Fpwheel]

Thanks. Appreciate a lot. Will check all those things out

 

[Fpwheel]

An update and any more thoughts appreciated!

Swapped coil packs- no difference. Check with meter also ok
Checked compression- no noticeable difference in cylinders and look ok
New Lambda fitted (as well as the previous new plugs and leads)

The "not firing" on 1 is I find not actually true, it is firing in that with just that plug lead connected, it will kick on that cylinder. Just that it continues to run very rough, very rich smelling, looking exhaust and black plugs.

Have now 'vagcom cable' and 'fiat 3 pin to OBD adaptor' and VAG-COM software. The programme and port/cable work test out ok but when doing initial "TEST" the programme reports good COM port but "No interface found". This is with the fiat lead plugged into the test socket by the ECU and ignition on. I am doing anything silly?

And any other thoughts on why fuel so rich (air filter etc is all off the car)

Many thanks

 

[fingers99]

They do run very rich until up to temperature, after which they're OK (in good health).

MOT man should cane the ******** out of it until the cooling fan has cycled on and off a couple of times.

After that, richness may be a stuck open (or missing!) thermostat (engine will take forever to warm up), or faulty engine coolant temp sensor (blue coded sensor on the inlet mani). If that goes awol, the ECU can think the engine is cold when hot, so enriches the mixture regardless (equivalent of a car with a carb running with the choke stuck open).