Focus is stuttering when driving

awec

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Grolschevik

Something similar with my Fiesta. Was the coil pack.

JohnBoy26

Grolschevik wrote: »

Something similar with my Fiesta. Was the coil pack.

Be difficult to find a coilpack in a 1.6 tdci.

Grolschevik

JohnBoy26 wrote:

Be difficult to find a coilpack in a 1.6 tdci.

Ha! Guess I'm a victim of tldr!

martinr5232

Sounds to me like either a fuel pressure sensor or wiring going onto it.

awec

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punisher5112

Was fuel pump checked??

mikeecho

Have you tried cleaning / replacing the maf sensor ?
It's a very basic step that may have been overlooked.
And can be done as a diy job

awec

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awec

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mikeecho

awec wrote: »

Would that cause these symptoms?

Loss of power, stuttering

I'll be doing a maf sensor clean and bg44k treatment on the Mrs car this week.. it is a petrol btw.

But.. cleaning the maf sensor is very easy as a job.

With a diesel., pop in some bg244. Clean the maf sensor. €50 job max.

Worth a try.

punisher5112

awec wrote: »

I believe so, but again, wouldn't this be a more consistent thing?

My Mondeo is doing this and it turns out it is fuel pump. Complete loss of power and basically goes into limp mode but not always.

awec

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NickNickleby

Hi,

We had a Focus 06, 1.6 Petrol. Edit: hahahaha , stop reading now, after posting I read the first post properly and see the giveaway (TDCi) . Apologies. leaving the rest, as I spent ages typing it...

It started performing badly, stuttering, but not all the time. A bit like a spark plug failing. After a web search, followed by using one of those OBD code readers, replaced the coil pack (€50 from Mick'Garage). Problem solved. Or so I thought.
12 months later, same problem. So, I thought to myself, this can't be a failing coil pack again, after all its a Bosch so a good name. Turns out, its not the coil pack, its the little three pin plug going into it. The pins in the coil pack become oxidised over time and affect the operation. A scan with one of those OBD things give a code saying 'low voltage secondary side" or words to that effect. I figured out it was the connector after I disconnected the coil and then reconnected it. THe problem went away for a week. Then I removed the plug again, this time using contact cleaner on the pins in the socket on the side of the coil pack, and also sprayed lots into the plug. This fixed the problem for another year.

this is such a well documented problem , that there's a guy in England selling replacement plugs. THe problem is that the loom is measured almost to the nearest millimetre , so there's very little play for working on it. The result is that the hardest part of doing this fix is actually unplugging the B*st*rd plug from the coil pack - and I'm not joking when I say that. My approach is to remove all the HT leads, then remove the 4 bolts holding the coilpack in place, then inverting the coil pack to make removal of the plug a little easier.

It worked for me, hopefully it'll work for you.

and for a further bit of useless information, when it first started happening , there'd just be a 'hiccup' in power, then all would be fine. I thought it was being caused by the toll sensors on the M50, that's how infrequent it was!!

hope this helps, and believe me , I'm very confident its what's happening in your case. by the way, I believe it can damage your catalyctic converter over time. something to do with unburnt petrol getting into the exhaust system.

cheers.

awec

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NickNickleby

awec wrote: »

Cheers Nick, but I am pretty sure it's not that, there are no coil packs in a diesel engine.

dang, in my defence, I spotted it immediately after posting, so edited it but you're too quick of the mark for me!!

Good luck with it.

chicorytip

Does this happen at higher speed only or also at lower speed? If the MAF sensor was faulty the car would tend to be very hesitant when driving off in low gear but would behave normally at higher speed.

awec

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punisher5112

Throttle body can be an issue like above also.

...And Justice

Had the same problem, turned out to be the turbo.

awec

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...And Justice

awec wrote: »

Was it really intermittent and usually only happened at high speeds?

Yep, had to take the foot of the accelerator for a brief moment then push down again to gain momentum

awec

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pm1977x

Hill Motors at Blackrock Dart Station are brilliant if that's not too far out of your way, ask for Austin.

mullingar

awec wrote: »

When driving along (usually on motorway but not all the time) it will feel like it is going to cut out for a split second and then drive on again. It feels like momentary jerking.

...And Justice wrote: »

Had the same problem, turned out to be the turbo.

A faulty turbo will not cause an engine to feel jerky.


Anyway, @ OP.

I'd say its either a faulty fuel pressure sensor or a intermittent fault in the wiring so you need to check the wiring for a loose connection. One option is to hook up a diagnostic reader to record all the main engine functions and hopefully it will occur during the recording (eg fuel pressure, air, turbo etc).

But, another low-tech method is to start the engine and start wiggling the wires in these 2 areas:
- fuel high pressure sensor, located back of engine, gearbox side, same level as top of gearbox, You may have to remove the air box assembly to gain access and make sure you keep MAF connected on the air ducting but you can have ducting disconnected.
- fuel pump regulator (back of engine, below the brake fluid reservoir)