Grey is over fuelling and is the unburnt diesel being passed through. As far as I understand
cheers :)
was wondering 'cause google mentioned burnt 'oil' as well.
..
under acceleration .. seen grey smoke on mine once , with the ronbox on a high/high setting.
and on an old vw-transporter .. after i tweaked the fuel pump.,
but both times , visible only under certain atmospheric conditions .. like a low mist.
.
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re. the turbo as a possible cause ..
it it could not provide enough boost .. for whatever reason,
then via the map sensor .. the ecu should reduce fuelling.
sort of puts aside the turbo as a reason. .. if the cause is too much fuel.
[ just thinkin' out aloud ;-]

i'd be tempted to use the hawkey live .. on the road.
i.e. whilst driver has their foot hard on the go-pedal
' see what data comes up .
[ if that's not already been done ]
.
 
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Turbo would likely throw oil in and that would be blue/ black ??
thinking the same here :)

i guess a vid. of said smoke eruption .. could help .. a bit.
i.e. for long distant diagnostic opinions ;-]
..
had a thought about .. what-if coolant got into the exhaust ..
would be steamy .. ;-/ ..
naaaah .. trash that .. a reduction of coolant would be noticed .. hopefully
[ and i guess .. ditto regarding oil consumption , if 'oil' were the cause ]
...
 
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So yesterday saw us remove the HPFP what a game that was, this FL1 seems to be fighting back all the time you do anything, or I'm just getting to old.

Anyways it's now on my bench ready to have all the seals changed.
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Hoping this solves it if not then I'm at a loss, and will need to go back to the drawing board.
 
Ok so the replenished HPFP did no good in fact the FL1 will not start at all now, the pump was refurbished to the book, tried a little quick start it sort of fired up for about 3 seconds then died again, no code to read only the ones where certain plugs had been undone those were cleared.

So we are now back at the beginning but in a worse place, next step is to see if we are getting fuel to the injectors, maybe check the low pressure pump and filter in the wheel arch, but it was working before started on the button but with smoke (grey)
 
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This one is giving you the run around isn't it?!?!

If it ran for a few seconds then we don't know if the pump will or won't cure the smoke issue.

Is there any rail pressure when cranking??

You get these teasers once in a while. What I hate is when you solve it and only then, the answer is obvious !!

Keep at it. We are right behind you 🤔
 
Ok so the replenished HPFP did no good in fact the FL1 will not start at all now, the pump was refurbished to the book, tried a little quick start it sort of fired up for about 3 seconds then died again, no code to read only the ones where certain plugs had been undone those were cleared.

So we are now back at the beginning but in a worse place, next step is to see if we are getting fuel to the injectors, maybe check the low pressure pump and filter in the wheel arch, but it was working be fore started on the button but with smoke (grey)
Thats a bugger…
I had something similar on my 1 once… I did some work on the fuel system, replaced filters and the LP pump. The thing would not start after… turned out I also had an intermittently dodgy camshaft sensor! (They don’t throw a code)
 
Interestingly mine did. Only worked when cold.
Well, that was the symptoms of my first dodgy one - wouldn’t fire up when warm.
The second dodgy one (that I found ‘by error’) was me replacing the first one with a cheap knock-off. Had an intermittent electrical fault I think.

Lesson learned.
 
This one is giving you the run around isn't it?!?!

If it ran for a few seconds then we don't know if the pump will or won't cure the smoke issue.

Is there any rail pressure when cranking??

You get these teasers once in a while. What I hate is when you solve it and only then, the answer is obvious !!

Keep at it. We are right behind you 🤔
Thats a bugger…
I had something similar on my 1 once… I did some work on the fuel system, replaced filters and the LP pump. The thing would not start after… turned out I also had an intermittently dodgy camshaft sensor! (They don’t throw a code)
Owner is today going to get a new crankshaft sensor just in case it got damaged when removing the starter motor, i doubt it will be though, not back there until Monday or Wednesday so will do Hawkeye test again.
 
More likely hp fuel rail sensor wiring or connector?
Hi Andy.
Once again thank you for your input it's always useful, the fuel rail as already had the upgrade harness fitted, what i don't want to do is throw parts at the car, need to track down why before the HPFP was refurbished it started on the button now it's not starting at all just not firing.

i suppose there is always the chance the HPFP could be knackered inside, or the ball bearing is stuck will give it a prod when i get there next time.
 

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