[Closed] Sudden loss of power under acceleration?? Fordfocustrackworld

I'd go for fuel or air starvation, so check the fuel and air filters are fitted properly. Does it rev freely when not under load?

If it is air starvation check the air intake pipes. Once had one that collapsed under load shutting down the air into the engine. One of the ribs had come out of it (it is like a fabric type air pipe from the filter to the engine).

Just remembered; had a new water pump and cam belt fitted at MOT in January.

I had this on the last focus

Worked out it was shitty fuel, the problem went away after a partial refill.

On my phone I found reset procedure that helped me get home without shitting myself

I have an '05 1.6 petrol so this may be completely irrelevant, but mine would misfire (or that's what it felt like) at low revs and high load i.e. standing start. Gave me a primary circuit fault via OBD2, so I changed the coil, HT leads and spark plugs (which were coincidently filled with water). No dice, whilst I was fitting and unfitting the plugs into the primary coil I knocked the leads leading to the primary coil and the engine stuttered like it did under load.

Quick google showed that this was "common" Ford Focus issue, and you could buy kits off ebay to splice in new wires. De-sheathed the leads, found the snapped wire and spliced it in. Problem solved.

I am not a car person, so my story may be of no use to you, sorry.

@plumber Do you mean the fuel reset switch? Car has had two £20 refills since this happened. One was BP and the other Sainsburys.
@jackhammer more of a car guy than me!

Could be dirty fuel, could be the turbo intercooler hose collapsing. Since you've taken to a garage for diagnosis there's no point speculating further on here until we know what they come back with.

Needing clutch at low speed is odd, you shouldn't have to do that, assuming you're in the right gear. I think that's a separate problem to the acceleration one. What revs does it happen at?

Fuel problem; air lock? -- as above check air intake pipe - my old Saab had a loss of power (though not shutdown) under hard acceleration, turns out the pipe had a split in it that was only presented when the pipe was fully inflated as it were...

Crud in the bottom of the fuel tank blocking the fuel filters because it was nearly run out of fuel. Engine starves for fuel under acceleration, but runs fine when just cruising.

My 14 focus just had a similar issue. Split in the turbo pipe. AA got Mr back on the road with a bit of fibre-fix.

we had similar issue - needed new turbo hose

As others have suggested, check air pipes for collapsed hoses or a post-turbo air leak (can you hear any whistling?). Lack of air will cause the smoke limitation to kick in which will cut your fuelling and so you feel a loss of power. At cruising loads you wouldn't see this as even ambient air pressure will feed enough air in, but on accelerations you are suddenly running very rich. Not sure if your particular model has a DPF, but if it doesn't then do you see black smoke out the back on hard accels (worse than normal)?

I also on that old Saab managed to run the fuel tank nearly dry and as above, all the sludge that was sloshing around the bottom got driven into the fuel intake, didn't end well..

i had the same last year, would cut out only under hard acceleration, as above i though checked fuel starvation and swapped fuel filter as it hadn't been changed under service for a number of years. not had an issue since.

Having issues again with my Berlingo. Cuts out power, but in my case the engine doesn't stop.

Codes saying Throttle Position Sensor, even though I've already changed it.

Possible related issue with yours perhaps.

I will go for EGR

Haha I just bought one of those OBD2 sensor things off ebay like this bought Torque off the app store and started googling the fault codes. Might be a good place to start.

I will go for mass airflow sensor (MAF) issue.

You maybe able to test that theory by unplugging it but it might throw a check engine light that potentially could require resetting if plugging it back in doesn't make it disappear.

So back from the garage who haven't taken the car out for a test drive and found no stalling or loss of power however have said that when they plugged it in straight away they had a DPF blocked fault come up and they dont do anything with those :/ The drive home was smooth and faultless, no issues at all.
There isn't any smoke coming from the exhaust and doesn't smell noticeably bad either inside or out. The fuel filter was changed under the master service in November and would like to think it would last slightly longer than that. The DPF was replaced almost two years ago (~£500) and the car has done around 18k miles since, the vast majority of that being motorway driving.
I am neither knowledgeable or confident with car engines and also in the middle or writing my dissertation so time is limited and would have no idea what I was doing or looking for and wouldn't have a clue if anything went wrong. A colleague has suggested another garage who they have found to be very helpful in the past so will speak to them and see what they say.
Fingers crossed as I'm not sure I can justify throwing another £500 at the car.
Arse...

The fuel filter was changed under the master service in November and would like to think it would last slightly longer than that

Normally, yes. But, if there's a buildup of crud in the bottom of the tank and you run it nearly dry, it can pick up enough to partially block the filter. It will still flow enough fuel for normal driving, but not enough for hard acceleration. Of course there could be other causes, but fuel filter is the first thing to check for symptoms like this.

My SMax did something similar a while back. Blocked fuel filter.

We had the split turbo hose thing, but the change in engine noise was pretty obvious alongside the drop in power.

Dpf fault could be dodgy sensor. Or as above could be from dodgy fuel and clogged filter. Have suffered “diesel bug” before that would only cause issues under hard acceleration

Feels like it resets and you get one good accelaration then reduced power but not quite limp mode and no codes recorded? Could be Exhaust Gas Temp Sensor Failure, Leading to DPF filter clogging and no Regeneration.

£800 regeneration and repair for a Ford Mondeo

Drive at 50mph for 20 minutes or more in a lower gear than normal to force regens.

Ive had a similar thing on my 06 focus TDCi 1.8, and a previous 1.6 diesel focus. both times it was the turbo hose/pipe. £80 for a new one from ford, second time the garage just did a bodge job. no problems since.

I'm surprised the garage don't do anything for a blocked DPF - not even recommend what you should do. I would Google for 'blocked DPF'. Two things about it, first how to unblock it, and second, find out why is it blocked. You're doing reasonable length journeys with motorway driving so it should get plenty of chances to regen. Plus it's relatively new - but why did the original fail? cbike's point is good, has a sensor failed?.

Was a genuine Ford fuel filter fitted at the service? The filtration levels required on Tdci injectors are very high- aftermarket filters often don't achieve this.

they plugged it in straight away they had a DPF blocked fault come up and they dont do anything with those

No idea what your problem is, but find a garage that knows what they are doing. A lot of the old school places are fricking clueless. They could of course might not fancy the job though.

What is your location? I have contacts in parts of the country who might be able to help.