Hi all, I am the mate of Phil's who has had the smoke on start problem, and I use the word "HAD" the problem, as the problem has just about (95%) been eliminated.....
Go get a cuppa, sit back, relax and read what we (Phil and I have done) .. It will open your eyes to some of the problems which overlap and give you headaches !!
I bought this car (2003 facelift model with TD4 engine) showing 85k on the clock, the service history was .... sketchy ... I test drove the car when the engine was warm and was vigilant about monitoring the smoke, engine temp etc etc as you do when buying a car you've only just seen, there are no oil leaks and everything works well, the chap I bought it from told me that it smoked a bit on start up but cleared after the engine was warm. Well I thought... leaky injector.. we (the company I work for) see this a lot, (I am a forklift truck engineer) so have plenty of experience of this type of problem, along with LPG systems, electrical systems (traction and automotive), hydraulic systems and all other things forklift related, I've only been in the trade for about 25 years so I'm still learning !! (i mean that) .. I have 8 other engineers who I work with and between us we have over 180 years worth of experience .. sorry about the background story but it is important, Phil has also been in the industry for over 20 years so between us we are more than competent. We deal with a number of "specialists" within our industry and have a good working relationship with them, we share information and have always managed to resolve any issues we've been presented with, some just take longer than others to work out, anyway lets get to the story.
We removed the injectors (at our diesel specialists premises) they were tested in front of our eyes on a £30k machine, two of them were slightly outside parameters on the fueling timing so all 4 were duly overhauled and refitted, at the same time we changed the glow plugs and Crankcase breather filter, we also checked the diaphragm that was in there, all were good, as Phil has said we had already changed the fuel filter (rear o/side wheel arch) what a lovely job that was! the air filter, etc etc, so a FULL service we could say, anyway I ran the car and it was certainly better, BUT the smoke still persisted, when the engine was not up to temperature I could hold the throttle at around 1900rpm and the (greyish / blue) smoke was coming out like a little steam train going uphill, so problem still there after injectors, filters and all other sensors checked and passed as operational, (we had swapped all the sensors off Phil's TD4 which works perfectly, having only done low miles with full history), so back to the drawing board.... My diesel specialist had said from the start that he comes across these on a fairly regular basis (1 a month on average) with this or similar problem, his solution has been to check the timing on his VERY EXPENSIVE equipment, oh forgot to mention that he and his colleague have been diesel specialists for over 30 years so have seen most problems on diesel engines, so timing checked he determined that the smoke was due to the injector still putting fuel in after the piston had reached or just passed TDC, so when the engine was cold the (TINY) amount of fuel which was going in at the wrong time (too late) was causing the smoke, when the engine was warm or near normal operating temperature it can easily burn of this really small amount of fuel within the combustion stroke so NO SMOKE WHEN WARM..
Ok, so let's re-cap, done everything possible to resolve the issue except timing which "can't be changed", well actually IT CAN'T, not electronically anyway,my own son re-maps diesel engines for a living, so I got him involved, he has access to a team of re-map engineers who he passed this information to, on the suggestion of my diesel specialist to see if it is possible to re-map the ECU to put in the fuel a little earlier to eliminate the small amount going in after TDC, so the re-map guys came back with a map, this map puts the fuel in at 6 degrees before TDC as it should, BUT it stops injection 1 degree earlier, the injectors still put in the about the same amount of fuel but the cycle finishes a little earlier, the theory behind this is that the engine probably didn't have an oil change for around 30k miles prior to me buying it, and as a result the timing chain / sprockets have worn more than they would have if they were running in nice new oil, it only takes a relatively small timing issue to cause this, as anyone who is familiar with the good old rotary diesel pumps will tell you, but at least you could 'spill time' these, anyway I digress.
So... new map duly programmed into ecu, this showed another problem up which I hadn't considered or even knew about, that was that the battery was only showing 11.88v whilst the re-map was being done, now I know that the ECU requires 12.4v before it can send out to all the sensors and get back an accurate reading, in turn it can then send off signals to the injectors for fueling, this is done with the crank sensor which tells the ecu when the pistons are 6 degrees before TDC and subsequently starts the injection process, so I checked the voltage at the battery on cranking when I re-started the engine, down to 9.2v at its lowest reading, but in a second the voltage was a healthy 13.4v, so alternator is working, and ECU is happy having full voltage, this made me think .... for the first second of ignition the ecu uses default settings as it can't monitor all the sensors accurately due to low voltage as the battery is turning the engine over.
So my theory about the initial fueling was wrong as it uses default settings???
Well NO, fuel would be injected into the chamber after combustion, leaving excess fuel on the next cycle (exhaust) when the engine is cold this wouldn't be burnt off properly, so causing excess smoke,
when the engine is warm then the fuel injected after combustion would be burnt of and exhausted on the exhaust cycle,
Remember, 4 stroke, SUCK - SQUEEZE - BANG - BLOW , if you put fuel in after the BANG then it BLOWS out unburnt as smoke,
but when hot this small amount of fuel would ignite in the chamber due to the high temperature and exhaust out burnt on the BLOW cycle.
So.. test drove the car with new - map ........ Oh My Goooooooodness .... Where had all this power come from ?, why was it smooth on acceleration ? Where has (Nearly) all the smoke gone at 1900 rpm? Why does it freely rev through to red-line without any hesitation ?
Well ... the only thing we have done beyond everyone else is re-map the ECU with an eco / performance map.
SO in "olden day terms' we've altered the timing slightly, like you used to do on your ford escort petrol to stop it pinking on that nasty cheap supermarket fuel !!
OH .... That's the other thing I've changed, the MOST IMPORTANT PART OF ANY ENGINE ....... THE FUEL ........ If you put crap in then you get crap out ... SIMPLE !
If you use low cost fuel - Morrisons - Tesco etc, then would certainly recommend something like Millers as an additive, or Comma diesel Magic as a 1 shot solution (as recommended by the diesel specialist and re-map engineer) or simply spend an extra few quid a tank on some good fuel like BP Ultimate diesel or similar, that's what I have done and it works a treat, nearly nil smoke, smoother, quieter, more responsive and I must say goes like a pocket rocket for a 2 ton slab,
One last thing I have learned is that the EGR valve is like a noose around the TD4's neck, I am getting rid of this over the weekend and I will report my findings early next week.
I must thank everyone for their contribution and a special thanks to Phil for his patience and understanding !!!!
I hope this helps you get to the root cause of your problem in some way, but I can honestly say it has cured mine !
Please feel free to comment .....
Dave.
********* OMG ********** The smoke is back at 2000 rpm ...... ***************** 13th Dec 2011
Sorry fella but this is total crap. If it's your mistake then fair enough but if this has come from your specialist then he ain't that special and you should stay well clear.
