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Ducati750cc · 28th March 2021, 10:14

If it's drawing air in from somewhere that can cause it to smoke i've been told.

Black smoke is mainly due to a fuelling / air problem, either excess fuel being injected for the amount of air drawn in or insufficient air drawn in for the amount of fuel injected, both amount to the same thing an over rich mixture.

If you had a leak in the intercooler pipework, air would be blown out, not sucked in, it is at whatever pressure the turbo is producing.

When flooring a turbo diesel from low revs or idle there will nearly always be a puff of black smoke initially, this is due to the amount of fuel your foot is asking for being injected almost instantaneously before the turbo has time to spool up to pressure, the exhaust returns to normal when the fuel to air ratio is correct a second or two later.

If you keep your foot down does the thick black smoke continue, or does it settle to a normal exhaust ?

You need to check the whole air side of the system from air inlet through to the inlet ports for restrictions, also that the turbo pressure and air flow is within spec.

Intercoolers can be partially blocked, rare but not unknown.

Next is to check fuel side to ensure that the fuel pressure is correct and that the injector dwell time is as it should be.

Another odd one is a partially blocked silencer that causes an increase in exhaust back pressure

28th March 2021, 10:14	#32
Ducati750cc Loves to post Rover75 tourer Join Date: Jun 2018 Location: Ashton Posts: 428 Thanks: 121 Thanked 206 Times in 145 Posts	If it's drawing air in from somewhere that can cause it to smoke i've been told. Black smoke is mainly due to a fuelling / air problem, either excess fuel being injected for the amount of air drawn in or insufficient air drawn in for the amount of fuel injected, both amount to the same thing an over rich mixture. If you had a leak in the intercooler pipework, air would be blown out, not sucked in, it is at whatever pressure the turbo is producing. When flooring a turbo diesel from low revs or idle there will nearly always be a puff of black smoke initially, this is due to the amount of fuel your foot is asking for being injected almost instantaneously before the turbo has time to spool up to pressure, the exhaust returns to normal when the fuel to air ratio is correct a second or two later. If you keep your foot down does the thick black smoke continue, or does it settle to a normal exhaust ? You need to check the whole air side of the system from air inlet through to the inlet ports for restrictions, also that the turbo pressure and air flow is within spec. Intercoolers can be partially blocked, rare but not unknown. Next is to check fuel side to ensure that the fuel pressure is correct and that the injector dwell time is as it should be. Another odd one is a partially blocked silencer that causes an increase in exhaust back pressure __________________ Common sense isn't a gift, it's a punishment because you have to deal with everyone who doesn't have it.