My wife's Focus has picked up an odd issue and misfires when warm. It started off as an intermittent thing, but now every time the engine warms up it misfires from around 2K-3K and struggles to tickover.

I have cleaned the MAF and put some Wynn's into the Inlet Manifold for the EGR Valve.

I am thinking maybe the Glow Plugs, but can only access 2 of the 4. The EGR is a bugger to take off as only 3 of the 4 bolts are accessible.

Any ideas welcome?

 

Mike

I am going to replace the Fuel Filter tomorrow and Oil + Filter. I will also take the EGR Valve off as I think it was the Fuel Filter blocking access to the final bolt.

diesels don't miss fire as such.

do you mean that it losses power under acceleration which will feel like it hesitates.?

If so then its  probably your fuel filter, potentially DPF. 

Could be a bunch of other stuff too but fuel, either the filter or the pressure sensor, would be towards the top of my list.

 

 

Thanks for the reply.

It is like a juddering/complete flat spluttersy spot between 2-3K, but only when warm. It's gradually gotten worse over the last couple of days.

I am changing the Fuel Filter/Pump tomorrow. I will see how I get on!

your changing the pump? that's an expensive start. do you have an ELM327 device and forscan to use? this will help narrow down the problem

if you don't, we highly recommend picking up a device from http://www.spanglefish.com/TunnelratElectronics/index.asp?pageid=516992

Ive got a few of them and haven't found a dud.  the chap is dead good if you need to contact him for anything as well

Fuel Filter, Air Filter, Oil, Oil Filter all changed. No difference and the car splutters and jolts forward quite harshly around 1500rpm, but only when warm.

It is doing something new, it is now in Limp Mode and I have the yellow engine light on. I will check it on the code reader later. The garage said it was picking up a DPF fault code, but this was changed about 18 months ago and the sensor about 6 months ago.

Ash Accumulation fault code, which is odd and may just be due to being driven on tests to find out what was causing the juddering/spluttering....?

Not sure of the next step.