Misfire - replace loom?

[GoldenWonder]

Well, two or three times in the last couple of weeks my 120 CDTi has 'misfired' at about 2000rpm

I understand this is pretty common and is to do with the wiring loom, with cylinder 3 being the main culprit?

Question is, is this an easy DIY job? (i.e can I do it on a driveway in the p-ssing rain!) or is it more involved?

I'd rather fettle this now than wait for it to get much worse. Typically the car is also due a cambelt,oil change,mot and brake fluid change as well

[Gsi3.2]

you don't replace the loom as such..more like 'repair' it...

to confirm it's the injectors ( which i doubt because when they suffer the wiring fault the car runs on 3 cylinders regardless of RPM ) you can unplug the injectors at 2000rpm one at a time.. if the engine is unaffected by the single injector being unplugged then that is the faulty one..but i still firmly beleive it's not the injector loom..

Do you have a management light lit? or a car and spanner symbol?..

[GoldenWonder]

Hmm, I don't have any warning lights on. But this happened about 4-5 times in total in the last 6 months.

Its not bad, but diesels don't normally 'miss' like this do they?

[CHRISSMART41]

Hi

Are you sure it is a misfire?

Does it happen approaching a junction at say 30 -40 mph in fourth or third gear on a slight incline and then stop. If it does, it may be a judder from the transmission, i.e. the dual mass flywheel.

[GoldenWonder]

Its a miss/hesitation usually when accelerating in 3rd gear at around 2000rpm. Like I say, its only happened a few times, but they're getting closer together!

My old renault megane used to do this all the time when the engine was cold. But that was a petrol engine and the hesitation seemed to have been a known fault on that model.

[Gsi3.2]

is it just 3rd gear... not any others?...

if it was the injectors or the swirl valves it would do it in every gear and when revved in neutral..

[GoldenWonder]

Its always seemed to be in 3rd, but that could just be coincidence or my driving style (I don't rev it much!)

I didn't think the 120 had swirl valves?

It definitely feels like a miss, not transmission or mechanical and theres no noise or vibration when it happens. It only lasts a second or so.

I'm off out now - I'll try and get it to happen again!

[GarthTax]

Sorry if This sounds silly but I have had the same problem for 3 years now. I have noticed it only dose this when the outside temp reaches 17。c . Did you get to the bottom of this fault . Thanks

[tommytonguedj]

My cdti 120 had this problem for a couple of years before i bought it, IT had all injector plugs replaced and alot more it turned out to be the throttle body needed resoldering of which i found and soldered, if your going to take it off to check you may aswell fit the fiat egr perforated gaskets and clean the egr whilst off. HTH

[GarthTax]

Hth ?