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I have a problem with my Terrano producing lots of black smoke on acceleration, does anyone have any ideas? It is definitley not the turbo. It has been on 2 diagnostic machines which didn't shed any light other than a faulty fuel temperature sensor that has been replaced but it still smokes. A new air flow meter has also been fitted but to no avail although when you unplug the airflow meter and rev the engine there is no excessive black smoke although it is undrivable with the airflow meter unplugged as there is no power. One garaged has suggested that the pre combustion chambers could be damaged as the turbo was recently replaced and apprently when the turbo goes you can essentially end up with excess fuel as the engine starts running on its own oil as well but I can find no metion of the pre combustion chambers after a quick flick through a workshop manual. Another garage has said that the exhaust was getting very hot and could possibly be partially blocked causing the smoke but I have yet to investigate this. Sorry for the long explanation but I have now taken the car to 2 supposed specialists and they don't really have a clue whats wrong.
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I am not a mechanic and know nothing about diesels but I always thought they produced black smoke due to faulty injectors?
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Hi,
many thanks, I think that is going to be the next thing to try and then fuel pump after that!
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Ernie
Black smoke is too much fuel - or not enough burnable air. A stuck-open EGR valve will give that condition.
Don't forget the basics like a blocked air-filter - particularly if it's been wet.
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Hi,
unfortunatly it doesn't have an EGR, even tried running it without air filter still smokes! Many thanks
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Ernie, did this problem start when you had the new pump fitted, does the vehicle run well enough for you to be sure that the pump has been timed in correctly?
I hope its a good old fashioned mechanical pump.
Assuming the timings ok, is it a Bosch pump? if so there should be two adjustment screws on the back of the pump IIRC, one should be the governer screw, the other should be a fuel adjustment screw.
You could slacken off the locknut of the fuel adjustment screw and unsrew anti clockwise for 1/4 or maybe half a turn to lessen the fuel, do mark the screw head or make a note of exactly where it was before doing so obviously.
If its a CAV pump then they can be adjusted similarly but i don't know how myself.
Did the new pump/recon come from a reputable source?
Its always worth giving the motor a good dose of millers anyway, it should help to clean up the injectros over a few tankfulls.
One other long shot, have you checked the air intake to see if a lump of rag or other debris is lurking about?
If your anywhere near the midlands 'Northampton Diesels' used to be The people for problems, but i haven't dealt with for many years.
EDIT, sorry misread, you havent had a new pump, my mistake, but the rest still stands.
Edited by gordonbennet on 01/11/2008 at 12:13
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Its had a replacement turbo but not pump. Tried injector cleaner, I used Tec 2000 and put it stright into fuel filter for maximum effect but didn't make any difference at all. I believe its not a mechanical pump, Nissan have seemed to put al sorts of electronics on this engine to make it overly complicated!! I also have a D21 Nissan pick up with the same TD27 engine but a much more basic and reliable version! I've even tried running it with the air filter assembly removed but it made no difference, I'm half tempted to up the boost on the turbo to try and burn off some of the excess fuel!
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What happened to the EGR valve? How was it removed and why?
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It never had one from new by all accounts
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Ernie
I'd check that fact if I were you; I find it impossible to believe that a Japanese diesel wouldn't have one.
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Ernie is this engine the td27? td27AA?
If it is we fitted this engine in the nissan forklift truck range from new, these cylinder heads used to crack between the swirl chamber and the valves causing lots of black smoke & they did not have turbo's.
We sourced heads easy enough but they would not repair.
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I believe its the td27 R20 engine. Your idea sounds plausable as a garage said a similar thing. I've swapped the injectors and it made no difference. One interesting thing is that if you unplug the air flow meter the smoke stops but the vehicle is not really driveable as the engine wont really rev when under load, must be something to do with the ecu not getting a signal from air flow meter and I guess being in get you home mode. Sounds like taking the head off might be a good option. I'm assuming the cracks are obvious to see once you take the head off? Many thanks for the advice.
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hi ernie
I also had this problem with my 2000 terrano td27ti engine.I replaced air mass sensor no avail turned out that the sensor was the wrong one i bit the bullet and got one from nissan perfect sweet as a nut.As said earlier black smoke is a sign of lack of air or overfuelling. If your'e head was cracked you would surely have oil in water or visa versa.I would suggest you take car to nissan i know this option sucks but sometimes its the cheaper option.Also if you take head off these heads only ever crack between pre combustion chamber and valve seats but also between the seats themselves.I also have a friend who has his own cylinder head company you could give him a call and see if he can shed light on it.His name is mark and number is 01706826260 company is engine express hope this helps.
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I take it that your 'friend' is happy for his phone number to be posted on a public forum?
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