[briwyle]

hi , my engine is hunting intermittently on starting it this morning i noticed the outside temperature was 3.5 degrees .on starting the car it was idling perfectly but after driving it for a while and then starting it again later it started hunting again i am at my witts end with it now as i've had it in to bmw themselves and several other garages that are mainly bmw "specialist" and they can't seem to find a problem . been diagnosed with no faults apart from the one time several codes which were reset and i was told was not a problem , i did notice one code on the report that said 4590 which is the rail-pressure plausibility delivery control does anyone think it could be to do with the sensor at the back of the fuel rail ? as ive read a few threads that say they have changed this and it solved the problem i have also read that it dont need coding ? but according to my manual it says that it does ?has anyone else had the same problem with there e90 ? and if so have you been able to fix it or get it fixed without it costing the earth ? i should also state that no lights are coming up on my dash ?
TIA
kind regards mark

[stringy93]

Mine does the same mark, Ive had it at bmw aswell and they said they couldn’t find a problem. It’s done it since 45k and it’s on 95k now and never got any worse. I’ve read all sorts, some saying a low battery could be the cause. Mines in at bmw next Friday for it’s service so I’ll mention it to them again. If they find anything I’ll update on here

[briwyle]

Thanks for the reply. Mine started doing it at around 13000 miles and considering it’s a common problem no one seems to know the cause of it . I’ve been told about a million things it could be and I’ve done some of them and it still does it. Hopefully you find out more when you take it in. Look forward to hearing about it.
Thanks again

[briwyle]

You should mention to them about the fuel pressure sensor on the back of the fuel rail as I’ve been reading on another forum . That a lad had he same problem and the garage changed this and it solved it . I’ll have a look after and post the link to the thread

[briwyle]

https://www.bmwfanatics.co.za/archive/index.php?thread-74296.html


Here’s the link I found

Regards
Mark

[stringy93]

Little update, dropped the car off this morning for its service and mentioned the hunting. Got a call this afternoon asking to keep the car, they are putting in to replace the whole fuel system, new pump, new tank etc etc. Not sure as to why yet but will find out more on Monday. Fingers crossed bmw warranty play ball! He did ask if I’ve ever misfuelled it, which I haven’t. And it’s always run on bp ultimate. So we’ll see what happens....

[stringy93]

So an update for anyone who might stumble across this with the same issue. I picked my car up from bmw this afternoon and it seems spot on! It’s had an eye watering £6k in parts replaced!! New fuel pump, all new injectors, new lines, new tank etc etc. Basically the entire fuel system. They didn’t go into details but are sure it was caused by contaminated fuel, however I’m not sure how this was possible. Anyway thank god for extended warranty, they footed the full bill 👍🏼

[briwyle]

thanks for the update , i,ve always thought its to do with fueling but i certainly ain't going to spend 6k on my car , i could buy a better one for that sort of money as i have no warranty on my car ,