2004 Ford KA engine misfire

pitachu

My wife has a 2004 KA (Duractec Engine), it has ~120000 miles on it has been serviced regularly (she's had it from new) and just before Christmas it developed a misfire.

We took it in to our local garage who scanned the fault codes and as a result replaced the coil, leads and plugs. This fixed it for a few days but then the misfire came back.

The fault codes were now showing a lambda issue, so I fitted a new pre-cat sensor myself and again that fixed things for a while but the issue came back.

The garage have had it back in since, checked the coil, leads, plugs and sensor (all are apparently fine) but can't get to the bottom of it so I thought I'd throw it out to boards.

The misfire only occurs once the engine is warm and under acceleration.

Replacing the car is not really on option right now and I really need to get this sorted as quickly as possible.

Any suggestions on what to check next are welcomed.

Mycroft H

They're notorious for having dodgy coil packs. Cheap enough to replace. Also worth looking at is the crankshaft position sensor.

dgt

Where do you normally get your petrol? What other sensors have been checked?

pitachu

Coil pack has been replaced already just before Christmas along with leads and plugs.

Mechanic suggested petrol as a possible cause, we tried using a different station for the last few fill ups but it has made no difference.

I don't know which other sensors have been checked, which ones should be checked for this kind of problem?

jimgoose

This kind of thing can also be caused by unmetered air, that is an air-leak somewhere upstream of the throttle body. Check out the plumbing between the MAF and the inlets.

noelf

pitachu wrote: »

My wife has a 2004 KA (Duractec Engine), it has ~120000 miles on it has been serviced regularly (she's had it from new) and just before Christmas it developed a misfire.

We took it in to our local garage who scanned the fault codes and as a result replaced the coil, leads and plugs. This fixed it for a few days but then the misfire came back.

The fault codes were now showing a lambda issue, so I fitted a new pre-cat sensor myself and again that fixed things for a while but the issue came back.

The garage have had it back in since, checked the coil, leads, plugs and sensor (all are apparently fine) but can't get to the bottom of it so I thought I'd throw it out to boards.

The misfire only occurs once the engine is warm and under acceleration.

Replacing the car is not really on option right now and I really need to get this sorted as quickly as possible.

Any suggestions on what to check next are welcomed.

Have you Googled Ford ka duratec engine misfire ...

pitachu

Yes I have, it mostly points to all the things we've changed so far - coil, leads, plugs and pre cat lambda sensor.

cutdoggy

Ive the same issues with my mk1 2001 ka. Rough Idle. No power under acceleration. Drinking juice. Its kicks like a mule in low revs makes an awful splutter noise when put the boot down on gos nowhere fast. A mechanic sat in my car and said he was 99% sure my cat was blown. So me the idoit replaced that not the problem of course. Ruled out 02 sensor/lamda cuz wouldnt cause such bad performance. So then I changed the sparks plugs with genuine ford plugs. No joy. So have coil pack and gona give it a shot. Dont no if that helps at least your doing it in the easier order. Dont start with the cat. Id wrecken thats ur issue put do not take my word 4 it

cutdoggy

Ive the same issues with my mk1 2001 ka. Rough Idle. No power under acceleration. Drinking juice. Its kicks like a mule in low revs makes an awful splutter noise when put the boot down on gos nowhere fast. A mechanic sat in my car and said he was 99% sure my cat was blown. So me the idoit replaced that not the problem of course. Ruled out 02 sensor/lamda cuz wouldnt cause such bad performance. So then I changed the sparks plugs with genuine ford plugs. No joy. So have coil pack and gona give it a shot. Dont no if that helps at least your doing it in the easier order. Dont start with the cat. Id wrecken thats ur issue put do not take my word 4 it