bmw diesel hot start problem

[bigstraight6]

learned colleagues, I have an anoying ongoing problem with our old BMW 325td where it's not hot starting as it should, it takes a fair time to crank over and when it does start there's a large plume of smoke from the exhaust, cold starting it's fine.

 

The car is well looked after and has been serviced every 6 months and the fuel filter replaced at 12 month intervals, I replaced the glow plugs about 2 years ago and recently fitted a 'magic box of tricks' relay which I found on ebay which tricks the engine into thinking it's cold at all times which I was really hoping would have solved the problem but it hasn't I didn't wire the unit in as I don't do electrics! an auto electrician friend of mine did it and the relay is working as I've had 'er indoors crank the engine over when hot while I've held the relay and felt it click.

 

Any ideas chaps? could it be a faulty temp sender?

[kinkersaab]

i hope im wrong, but i expect it is the pump, not had one for a few years, but got caught out a few times, eventually the idle when warm will give probs too, I never bothered trying to fix any of them as price was preventative, just threw them back through the ring, i think its quite a common fault.

[The Reverend Bluejeans]

Tank at least 1/3 full and a mega strong battery?

 

It could be a shagged pump (the one on the engine or the one in the fuel tank) or the glow plug relay. Good cold starting almost eliminates the in tank pump though.

 

Yes, it could be the coolant temp sensor.

[alf892]

I did see a similar problem on a BMW forum where the owner listed all the things he had done to cure this until someone suggested cam sensor. This cured it - try google!

[Owain-328i]

I did see a similar problem on a BMW forum where the owner listed all the things he had done to cure this until someone suggested cam sensor. This cured it - try google!

 

Think this is only an issue on petrol engines!?