Fiesta TDCi advice
Turbo Mini Forums

Sisters car.

2008 TDCI with 120k miles.
Occasional injector fault causing a misfire.

Would you change the one injector, or all four, or is other things likely to crop up soon.
It’s been well serviced and trouble free for her, but now she’s concerned about what she should do - the bare minimum and risk future unreliability, or jump on a new car.

I know I’d personally just change the one injector, and keep it as an ongoing maintenance and accept potential unreliability as I’m a cheapskate lol

So, looking for advice from you guys on if it’s worth putting money into a fiesta of these miles or is there a lot more that’ll go wrong potentially in the near future?

My TDCi engine (in a 2003 Mondeo) is beginning to exhibit the same although only when cold so far. 2008 is probably Euro5, mine's Euro3 but the injectors are pretty much the same.

There is a standard injector leakage test you should do which just involves buying 4 of the little plastic leak off connectors, some plastic tube and 4 plastic bottles, clip them in place of the real leak-off lines and run the engine through a series of timed RPMs and see how much you collect. The details are all on a Wiki accessed through the TalkFord forum in the UK. I have all the bits but am waiting for warmer weather.
You should also acquire a code reader, it might show you loads of related faults other than the injectors themselves. They also show running parameters like live fuel rail pressure which will tell you if the main pump is on the way out. There are some fairly cheap ones specifically for these engines but make sure you get one of the ones that can re-enter the injector calibration codes because if you do change any of the injectors, the ECU needs its specific code entering or the ECU will just inject as if it was the original and as they all have very unique flow characteristics (ie, they can't make them all the same) the ECU will throw up all sorts of other faults (like excess knock) and keep throwing itself into limp mode. (my ECU managed to corrupt two of the codes and it ran like shit until I pulled the injectors to read the physical codes off them and re-enter them, the paper label on the rocker cover with the original codes was damaged so I couldn't read them from that).

Long term, these early common rail injection engines are a money pit. Euro5 onward they were getting better but there are no cheap parts on them.

Schrödinger's cat - so which one am I ???

Link to the test for the Mondeo engine.

http://www.talkford.com/community/page/for...k-off-test-r121

It's probably the same for yours but just work back up the directory and select the right car/year to be sure.

Schrödinger's cat - so which one am I ???

on the fiestas, if it's the engine style where the injectors are burried under the inlet, remove them all and replace the copper seals and leak of pipe.seals. do not under any circumstances even try and clean the injector tip. the nozzles are so tiny even just wiping the carbon off with a rag can block them. this seems to be an issue particular to these tiny diesels. I've had 4 I. from other garages with missfires after seal replacements and afaik cleaning the tip was the reason(usually with a wire brush). cleaning the rest of the injector is obv ok.

if yours is the newer style with the injectors exposed, just change the offending injector and call it a day. perfectly fine to do. in my experience the fiesta injectors will run fine without entering the trim data. I always do, but plenty garages don't and tbo it never seems to be an issue on them. the fiestas are also way more reliable due to the pump design. the MK3 Mondeo's were more finicky as they were using piezoelectric injectors while everyone else was using solenoid injectors, now everyone uses piezo but ford (1.8 and 2.0 tdci) and Renault(1.5dci) did suffer from the early adoption of this tech. imho.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Well, here is a pic of the engine room.

Certainly looks like injectors are buried.

yeah that'll be the earlier Siemens system, if there's no evidence of carbon buildup around the non-offending injectors you can leave them as-is. I always change the seals but I have to warranty my work lol you don't technically have to but I highly recommend you remove the wipers and upper and lower scuttle panels it will greatly improve access. and remember the two bolts which will be hidden down the back of the inlet/cam over . you have to pry fairly hard to remove the inlet so easy to snap them if forgotten. you can also start the engine with no inlet if required while diagnosing(for example to do a leak off as suggested) you just need to put some card over the exposed camshaft and make sure nothing falls down the intake ports lol

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Well, I’m not doing the work as I’m back in the land of V8s
Sending you a PM Denis

Edited by TurboDave16V on 10th Apr, 2018.