Hard to start then white smoke

[drubie]

Originally Posted by emtheriddler

Thanks guys I had seen that thread but I was wondering nhow easy the readers are to use... Not mechanically minded but practical

If you buy something like the following and have an android or an iphone:
http://www.ebay.com.au/itm/Mini-Auto...item2c70a8f9f9

They are very easy to use. Plug them in and turn on your ignition, then use a phone app (I use Torque but there are others).

The biggest problem I found was that the thing made me chase my tail because I assumed that the problems it was throwing up were real, whereas most of them were self inflicted by me unplugging things I didn't quite understand at the time

However, for scanning error codes they are fantastic and cheap. Note that an engine can be running badly without throwing a code if it's something the computer isn't plugged into, can't monitor or can adjust for within it's operational parameters. You'd be surprised just how much they can adjust, I assume they are set up so that as the engine wears, it still functions.

[Macca2801]

The White smoke is typical of fuel being injected but it didn't ignite for a few reasons. This usually counts out all the position sensors and the fuel injectors as they are operating otherwise you would get a clear stack while cranking.
For it not to ignite, then you really have two possibilities and that's heat or timing.
you may have a timing issue if one of your position sensors is erratic and the ECM is playing with flipping firing the companion cylinder to see which is actually at TDC on compression. This will give an extended cranking time and smoke on final start. Although this will most usually throw a position sensor fault and mil light.
Finally heat, hard with Direct injection unless you have slow cranking speed or sub zero operating conditions. Glow plugs are just about irrelevant and although they do heat in most circumstances they arent actually needed, so although possible it's unlikely its glow related.
Is it cranking any slower than normal when it struggles to fire??
With my JK I get the exact symptoms you are describing if I haven't driven it in awhile. My D31a is 5 years old so I know it's starting to struggle but its hanging in there. So, if it's run down from sitting idle and I just turn the key to start without pausing in the "on" position it will crank slowly and for a huge amount of time....and occasionally not start (well I kill the cranking after about 5 secs). If it does start like that it's with a huge amount of white smoke from the fuel injected while cranking.
If it takes more than 5 seconds then I drop to "on", wait till priming pump stops and try again....even with the slow cranking this always fires in a few seconds.
In comparison, if the battery has just come off charge or it's been driven daily then I just touch the key to start and let go and it fires immediately.
It's amazing how sensitive modern diesels are to cranking speed, I guess the CR pump and compression temp both need good revs to get the pressure required for easy start.
So if it's slow at all and you are certain the battery is perfect I would also look into volt drop testing the starter circuit and maybe even check the starter motor.
Goodluck, takes patience and methodical elimination to good fault finding.
Matt