4b10/01 engine roughness regulator - Fault code help please!

[crash]

Gents,

After my 3.0d 55 X5 started idling lumpy/ juddering a few days ago i thought i would finally get the scanner plugged and and see what it had in store for me!

Along with the usual glow plug faults it also threw in a "4b10/01 engine roughness regulator" fault code.

I would assume it is related to the injector flows? due to the lumpy idle and strong exhaust fume smell that would indicate over fueling/ incomplete combustion.

I cleaned out the EGR valve, replaced the PCV breather and did the air filter yesterday just to get those ruled out the equation.

Any advice before i drag it down to the diesel injection specialists and start pulling injectors??

Thanks in advance

Ash

[X5Sport]

Make sure all your vacuum hoses are (a) connected and (b) intact.  Air leaks can also cause upsets and these are the simplest to check for before you start spending money.

Did you disturb any of the injector wiring?

Might also be worth taking the engine cover back off and having a look and a very GENTLE prod of the cables to each injector just to see if it all settles again.  No money cost to do, just time.

Richard

[crash]

Richard,

Did all the filter/ breather changes after the lumpy idle started!

Checked all the vacuum hoses while doing them and all looked in good condition and connected.

Also gave all the injector wiring and technical wiggle and prod just to rule out connection issues. Made no difference!  :wall:

It all started after a 20 mile motorway trip, pulled into the garage for redbull top up and when i started it 5 minutes later i was greeted by the judder on idle!

[X5Sport]

Spheroids!  That's all the obvious things covered.

If it was the fuel pumps or fuel filter I would expect the issue at all rpm, so that's unlikely.  If it's running at normal speeds then that may point to the injector correction values according to a web trawl, and that means a new injector(s) as they aren't repairable.

If you have access to the INPA system then that would tell you the values so you would know which was the most likely culprit.

Not sure if the car would tolerate you pulling the plug on one injector at a time to see which one made no difference?  Someone on here might gave the answer to that one.

Richard