Is220D Missfire

[pupster]

Hello,

This is my first venture onto this Forum and I have a problem that I would like some guidance on. I have a IS 220D 2007 that has a flat spot/missfire in the 1500 to 2000 RPM Range in all gears. Looking at some of the forum entries the usual suspects came up such as the EGR Valve and air filter as probably being the most likely cause. I have had the car for a week now and looked at the EGR valve which was as clean as a whistle along with the connecting pipe but decided to give it a good clean anyway. I then looked at the air filter and that was in need of changing which I have done but still have the same issue.

Now looking at changing the fuel filter as it does feel like a fuel related issue but just wondering what else I can check before I have to go and have it diagnosed. I cannot see anything obvious and the engine does idle as it should and there are no leaks that I can see.

On the motorway in 5th and 6th gear I can feel the engine not pulling as it should but when I boot the car in a low gear it does accelerate as I would expect.

I would be most grateful for any pointers..

Pupster

[Captain Fizz]

On mine there's no power sub 1500 RPM, moderate power until 2k then decent power all the way to 4.5k.

This is due to the turbo.

Generally can't use 6th gear, even motorway driving.

Is it just that between 1.5k and 2k the power isn't great?

That's normal I believe...

[pupster]

It does seem that all of the info I have read on this subject that this is pretty common but it's not really a lack of power it's more like a roughness rather reminisant of fuel starvation between 1500 & 2000 revs. Been reading a lot on the subject and was wondering if I diconnected the MAF to see whether I still get the problem or at least eliminate this from the cause.

I am thinking of using some BG244 diesel treatment additive to see if this improves things but will need to change the fuel filter first.