My fiesta has been sitting for a while and I drove it today for the first time. The engine light came on briefly and then turned off. The next time I turned the car on (still warm) the belt sounded very different. All of a sudden the car started jolting back and forth with slight loss of power. This only happens every so often. My engine light is now on and hasn't turned off.

Is this a misfire or a belt issue..? Or something else?

Not sure if belt would cause engine light to come on. Really needs code reader putting on it to give some pointers. Eg a code reader from somewhere like tunnel rat electronics and free forscan software. 

4 minutes ago, isetta said:

Not sure if belt would cause engine light to come on. Really needs code reader putting on it to give some pointers. Eg a code reader from somewhere like tunnel rat electronics and free forscan software. 

I believe its a misfire. I started it up again and it sounds like a tractor and smells of petrol. It sat for a year on an empty tank. Maybe a blocked fuel filter

What engine? Diesels have fuel filter. Not sure about the petrol engines. 

4 minutes ago, isetta said:

What engine? Diesels have fuel filter. Not sure about the petrol engines. 

I have petrol. Theres a filter I changed it last year when i got the car but after running on almost empty for months it might have blocked up. Also just noticed and large amount of water in the spark plug wells. Just dried it up so hopefully that helps..

Engine has been misfiring intermittently in cylinder 4 judging by the first code. The car has been sitting for about a year on almost 0 fuel and I drove it yesterday for the first time when it started happening. I did find a lot of water in the spark plug well and have now removed the majority of it (I don’t know if that was the problem). Any ideas?

Just a few things to think about from my experience with my 03 Fiesta (had it 13 years now).  The 03 had an ignition coil pack that was revised later (so inherent issue on original?).  I’ve chewed through 2 of the original ones which failed and now have the revised one.   Consider plugs and leads also.

The plug wells are susceptible to holding water and what doesn’t help is that you can also have an issue with the window washer tubes (near the jets and above the plugs) leaking and dumping water into the wells.

Smell of petrol?  Unless you can see any fuel leaks under the car or in the engine bay, I’d say that’s unburnt petrol due to, as you say, lack of a spark at the pot…misfire.  Consequently then, it will sound and feel well lumpy, perhaps like a tractor missing on two.  I’d head that way first.  PS putting a car cover on it when not in use helps a lot.

Are you using fresh petrol?  Petrol does go off over time and can cause rough running if it's been in the tank for ages.  The filter won't be blocked up already, inline petrol filters can last 10 years!  Not the same as diesel filters that block up quickly with wax.

 

Looks like, battery voltage poor, poor quality fuel in tank, throttle body has gone out of sync

1 hour ago, DaveT70 said:

Looks like, battery voltage poor, poor quality fuel in tank, throttle body has gone out of sync

Changed battery about two months ago. It has been sitting since then but it seems fine. Fuel was my first thought. Why would the throttle body be out of sync? And how would you fix that?

2 hours ago, Marineboy said:

Just a few things to think about from my experience with my 03 Fiesta (had it 13 years now).  The 03 had an ignition coil pack that was revised later (so inherent issue on original?).  I’ve chewed through 2 of the original ones which failed and now have the revised one.   Consider plugs and leads also.

 

The plug wells are susceptible to holding water and what doesn’t help is that you can also have an issue with the window washer tubes (near the jets and above the plugs) leaking and dumping water into the wells.

 

Smell of petrol?  Unless you can see any fuel leaks under the car or in the engine bay, I’d say that’s unburnt petrol due to, as you say, lack of a spark at the pot…misfire.  Consequently then, it will sound and feel well lumpy, perhaps like a tractor missing on two.  I’d head that way first.  PS putting a car cover on it when not in use helps a lot.

 

I appreciate your help! Hopefully it’s something like HT leads or coil pack. And not catastrophic.. 

1 hour ago, TomsFocus said:

Are you using fresh petrol?  Petrol does go off over time and can cause rough running if it's been in the tank for ages.  The filter won't be blocked up already, inline petrol filters can last 10 years!  Not the same as diesel filters that block up quickly with wax.

 

The tank was run on nearly empty with petrol from 2-3 months old. Just filled up with fresh petrol so I’m hoping if the old petrol is the cause it will fix itself…

1 minute ago, CollumPlz said:

Why would the throttle body be out of sync? And how would you fix that?

 

That's what the codes are saying.

Replace fuel with fresh fuel

Disconnect battery earth with ignition on, leave on

Leave 10 minutes, whilst disconnected turn on/off headlamps and press brake pedal a few times

Reconnect earth with ignition still on

Get in car, close door, key out, open and close door

Handbrake on, A/C off, seatbelt off, FEET OFF PEDALS

Start engine - do not touch pedals

Leave engine to run for 10 minutes - do not touch pedals

Turn on A/C - do not touch pedals

Leave engine to run for one minute

Key out, open and close door

Should be OK

1 hour ago, DaveT70 said:

 

That's what the codes are saying.

Replace fuel with fresh fuel

Disconnect battery earth with ignition on, leave on

Leave 10 minutes, whilst disconnected turn on/off headlamps and press brake pedal a few times

Reconnect earth with ignition still on

Get in car, close door, key out, open and close door

Handbrake on, A/C off, seatbelt off, FEET OFF PEDALS

Start engine - do not touch pedals

Leave engine to run for 10 minutes - do not touch pedals

Turn on A/C - do not touch pedals

Leave engine to run for one minute

Key out, open and close door

Should be OK

Sorry can I ask what this does lol? Thanks for your help 🙂

1 hour ago, CollumPlz said:

The tank was run on nearly empty with petrol from 2-3 months old. Just filled up with fresh petrol so I’m hoping if the old petrol is the cause it will fix itself…

2-3 months old will be fine, it doesn't go off that quickly.  So probably not fuel related in this case.

1 hour ago, CollumPlz said:

I appreciate your help! Hopefully it’s something like HT leads or coil pack. And not catastrophic.. 

Yeah, new plugs, new HT leads and test the window washer pipes maybe.  Best of luck.

I'm starting to run out of options at the moment. The car is misfiring in cylinder 4 but don't know why. It has been sitting for a year without being driven and now it misfires. It isn't constantly doing it, only a little. The car sometimes jolts back and forth and often when you try accelarating, the car holds back and then the power kicks in but then straight off again... Changing gears seem to be a struggle, almost like the car wants to stall. I've done a test and had the below results however, I've tried clearing the PCM by removing negative cable off the battery and let it drain for 10 minutes and then start it again but nothing changed and engine light stayed. I noticed a lot of water in spark plug wells that I have removed most of it. I don't want to remove spark plugs and check because of the water. I don't want to drive it as it seems damaging. So I'm stuck at the moment. 

What do you think @DaveT70 , if he asks the question enough times he might get an answer he likes ?

3 minutes ago, unofix said:

What do you think @DaveT70 , if he asks the question enough times he might get an answer he likes ?

Im hoping more people can see my post and give me more advice as to what it could be... I appreciate all the advice already but hoping someone may have experienced something similar.

41 minutes ago, CollumPlz said:

Im hoping more people can see my post and give me more advice as to what it could be... I appreciate all the advice already but hoping someone may have experienced something similar.

You don't have to keep making new posts everytime. You'll just end up with the same replies as last time...

get this confirmed by others before you do it, ok so i had a escort yrs ago with water in the plug cavities rang my mate (a fitter at the time) he told me take the plugs out and with them out turn the engine over a few times. the water will drop through when you remove the plugs. but turning the engine over without them in will force anything back out of the plug holes. be worth trying to find out where the water is coming from though.

Water in the spark plug wells is a well known issue and there are lots of old posts about it for both Fiesta and Focus.
Various methods to remove the water, use one of those household spray cleaner bottle tops with the long straw and pump it out or attach a small tube to a wet n dry vacuum cleaner.

The water is rain water that seeps under the the offside washer jet onto the airbox and then finds its way into the plug ports. Remove the washer jets from the bonnet and seal them with silicone sealant.

The water can rot the core plugs in the head so if you're unlucky its not just rain water but coolant as well.

9 hours ago, YBTURBO said:

get this confirmed by others before you do it, ok so i had a escort yrs ago with water in the plug cavities rang my mate (a fitter at the time) he told me take the plugs out and with them out turn the engine over a few times. the water will drop through when you remove the plugs. but turning the engine over without them in will force anything back out of the plug holes. be worth trying to find out where the water is coming from though.

If you've sucked water in through the air filter then that's a last ditch attempt to remove it before a hydrolock.  But it's a bad idea to purposely let water into the cylinders by removing the submerged plugs first imo.  

The water does need to all be removed from plug wells before we'll get any further with this issue though.  Wet vac seems a bit excessive for this, I've managed it with a rag or paper towels.  Though I do like the spray bottle idea!

On 12/18/2021 at 9:37 AM, TomsFocus said:

rag or paper towels

Yup, mop it up first.  I’ve got a £5 Li-lo air pump that has a pointy nozzle I use for puffing the dust out from the PC.  Best £5 I ever spent. You could puff a fair bit of water out with it first if no air can or airline available.

1) Water out

2) New plugs, or if on a budget at least try cleaning and gapping the old ones

- Test again.

Still no joy?

1) New plugs

- Test again.

Still no joy?

- Try new HT leads

- Test again.

If still no joy, sorry to be the bearer of potential bad news, but you could do worse than to try a new coil pack (or known good one). 

Failing that, if you're as unlucky as me (believe it’s what happened to me) it is possible that the coil pack has damaged the ECU, so start thinking about what the car's worth to you and deal with that if viable.

Have you ever had the EAC fail message and limp mode?  You might want to look at this and few other instances of similar: https://www.fordownersclub.com/forums/topic/7158-eac-fail/