"Catman" > wrote in message
...
> On 10/08/2011 10:48, GT wrote:
>> > wrote in message
>> ...
>>> On 20/01/2011 12:13, GT wrote:
>>>> 156 2002, 2.0 JTS petrol. I (the car)had a splutter/cough a year or so
>>>> ago
>>>> and it eventually went away on its own. Its come back now and I would
>>>> like
>>>> to at least figure out what is causing it, if not fix it. The problem:
>>>>
>>>> Its independent of gear (done it in 3rd, 4th 5th). I don't tend to rev
>>>> over
>>>> about 4000 most of the time as its a nice torquey engine. Problem
>>>> occurs
>>>> under load, usually at around 2000 revs. It is repeatable - the 270
>>>> degree
>>>> slip road onto the M8 at the top of Livingston is about a 50mph corner,
>>>> 5th
>>>> gear. As I come out of it I speed up to er... 70 (ho humm!) and it will
>>>> splutter most times there. It also does it in 3rd coming out of the
>>>> silly
>>>> little roundabouts they stick along in-town dual carriageway 40mph
>>>> stretches. Its a cough/splutter, lack of power, followed by 'beep beep'
>>>> motor control failure - go to dealer. As I feel the splutter starting,
>>>> if
>>>> I
>>>> back off on the accellerator and just speed up more gradually all is
>>>> well.
>>>> If I drop a cog and increase the revs, all is fine.
>>>>
>>>> I have ruled out dirty fuel as its been through several fill ups.
>>>> I have rules out engine temperature as it doesn't make any difference.
>>>> I have ruled out spark plugs and electrics because the revs are low, so
>>>> the
>>>> demand is not so much - wouldn't this cause problems at higher revs
>>>> when
>>>> there are more sparks per minute?
>>>
>>> *maybe*
>>
>> I got a cable and diag software. I found 2 fault codes: P0300 - "Misfires
>> detected (generic) and P0303 - "Cylinder 3 ifnition failures".
>>
>> "The emissions Monitoring system has detected misfires, an Air/Fuel
>> micture
>> problem or other indicators of emissions exceeding the permissible level.
>> Check the plugs, ignition and fuel systems, and the ending mechanical
>> condition, and that the oild level is not too high, or oil change
>> overdue.
>> Defects contribute also to O2 sensor degradeation and premature catalytic
>> converter efficiency loss.
>>
>> The reason for this fault is that the EDU has received very high signal
>> from
>> the sensor. The fault is not is not detected now, but it is stored in
>> memory. Clear fault codes, and observe for future appearance of the same
>> fault. Dashboard warning light was activated for this fault."
>>
>> Sounds like the spark plug or wiring is failing on cylinder 3. I checked
>> out
>> the throttle sensor and whatever I did to the pedal, the software
>> reported a
>> valid position - I couldn't get the graph to flicker or jump at all.
>>
>
> <fires up babel fish>
>
> That's a bit bloody useless really, isn't it.
>
> 'You've got a misfire, mate' is really what it boils down to.
>
> Having said that, if it's flagging emissions exceeding the permisable
> level, would it be reasonable to assume that it's because the fuel / air
> is not igniting. If there was no fuel, then surely you'd get no emissions
> and then no excessive emissions?
>
> That being the case, I'd look at the plugs and such, but....
>
>
>> Any thoughts to add?
>>
>> So: My handbrake cable has snapped, cylinder 3 is knackered, the exhaust
>> has
>> shed its outer skin and can't have long left, the air-con gave up the
>> ghost
>> last year, I've spotted a few bubbles in the paint round the edges.
>> Otherwise, all is good in alfa land!
>
> Super. It's probably hit money pit land, I'm afraid.

Yes. Another 700 miles and I'll hit the magic 100,000. I'm despirate to
reach it on the original exhaust. It would be nice if all the cylinders were
still going too!! Its been misfiring like this for a few years, gradually
getting worse, but its not a major problem from a driving point of view. My
money is on something in the spark or even the injector department. If the
injector isn't working properly, perhaps its dumping too much fuel on one
cycle and not enough in the next. Unlikely I suppose..