The MR16DDT - Nissan TechNews
Contents
1. ECM shorter signals advance longer signals retard timing The signal moves the valve within the EVT control solenoid to allow for oil pressure to flow in a combination of two directions toward advanced or retarded Oil can also flow out a drain for displacement There is a return spring applying pressure within the sprocket toward a rest state If the signal pulse widths are equivalent both control solenoids will hold their sprockets in a stable position The intake valve timing IVT control solenoid operates identically to the above described EVT control solenoid except that the pulse nT NANA length behavior is opposite longer 720 NOTE Cam halt position sensor PHASE signal timing varies with intake valve liming control The unique design of the PHASE sensor plate Figure 5 makes for more signals advance intake timing and informative graphs above Winter 2015 9 MR16DDT shorter signals retard Also the direction of the displacement The MRI6DDT has great power per return spring force is opposite liter as a result of turbocharging Let s skip over With the CONSULT technicians can verify the how turbo works in general and instead focus on current cam sprocket angle using live data IN T V the specitic boost control methods used by this TIM at idle should be between 5 and 5 degrees particular engine cam advanced CA and between O 20 degrees Whenever the throttle valve is shut compl2. Feature n The MR16DDT ii ome Displacement Big Output __ A look at the MR16DDT turbocharged direct injection gasoline engine in the JUKE covering the engine design direct injection system turbo and continuously variable valve timing Also a few service procedures and diagnostic considerations for this engine s l i gt p The Nissan JUKE comes standard with advanced engine design and engine management systems that may become much more common across all manufacturers The reason is simple the MRI6DDT engine achieves a great balance of power fuel efficiency and low emissions Automobile manufacturers are under constant pressure to reduce their vehicles emissions while increasing fuel efficiency These gains are almost always at the cost of engine power and performance The engineers at Nissan have developed an all aluminum 4 cylinder 1 6L engine that boasts 188 hp and achieves approximately 27 mpg in a 3000 Ib JUKE The MR1I6DDT utilizes many technologies to achieve its excellent power etticiency emissions balance 1 Advanced internal engine mechanical design 2 Extraordinary fuel control through gasoline direct injection DIG 3 Continuously Variable Valve Timing CVVT 4 Forced air induction through turbocharging The JUKE also utilizes a high efficiency automatic transmission intelligent throttle control and other vehicle specitic systems The CVVT system improve
3. JUKE and JUKE NISMO editions You will tind a different spark plug a lighter weight OW 20 synthetic oil changes in the engine management system and different driveline lubricants and CVT options The net effect is a 1 2 mpg fuel economy improvement and 10 increased horsepower and torque The turbo s 1 boost is managed by the computer s signal to the boost control solenoid 3 based on input from the boost sensor 5 The boost control actuator 2 will then route a percentage of the exhaust gas into the turbo or back through the recirculation valve 4 Winter 2015 11
4. etely CA at 2000 rpm EXH V TIM is identical at idle the turbo produced intake air charge doesn t just but at 2500 rom and rising exhaust timing should stop and wait for the door to open again Pressure be between O 30 degrees CA will back up accumulating in the intercooler The most commonly observed failures with any Eventually pressure can stall or reverse the direction variable valve timing system is lack of oil pressure of the compressor turbine This can put heavy stress Without sufficient oil pressure VVT cannot on the turbine bearings and fins which may reduce operate and the MIL will illuminate with potentially reliability and longevity of the parts The MR1I6DDT misleading faults pertaining to valve timing Check mitigates chances of so called compressor surge engine oil level first before chasing a cam timing with computer managed boost control code down the rabbit hole The boost sensor is a second intake air temperature sensor that lives on the outlet side of Turbocharger the intercooler It can also sense pressure which Forced induction is a simple method of it sends to the ECM in form of a voltage signal improving engine pertormance without increasing Flow control diagram for CVVT exhaust sprocket Retard hydraulic chamber sprocket rotatory direction hydraulic A 4_f fi chamber Oil pressure gt DI PAWRRERAWEUEURE ERROR NEE TY aN Pressure A Drain it lie VTC returning Advance Ang
5. ime increases the greater the rail pressure will build More fuel per injection event will be delivered when rail pressures are higher The amount of fuel injected is a program value stored in the ECM based on engine operating conditions determined trom input signals generated by the crank position sensor POS camshaft position sensor PHASE mass air flow sensor MAF FRP and turbo boost sensor Higher load taster engine speeds everything that you would expect to demand more fuel is picked up by the ECM and the fuel pressure adjusted As with most cars a feedback Spill process Outflow process MR16DDT loop is established using air fuel ratio sensors to for engineers Do we design the engine with high maintain stoichiometric balance valve overlap for high RPM range operation Should The ECM can also modify fuel injection the engine be tuned for better low and mid range behavior based on special operating conditions efficiency Implementations of variable valve timing For example more fuel is added during starting acceleration hot engine operation shitting the Figure 1 4 Special service tools remove CVT from neutral to drive and high load Less fuel the press fit injector and install the suitable is added during high speed cruising and no fuel is replacement seal ring added during deceleration Direct injection allows for a technique called Figure 1 stratitied charge combustion The timing of the fuel injec
6. in work Do not restart the engine Continuously Variable Valve Timing Overcoming the physical limitations of valve overlap timing has always been a discussion of trade offs a Nicean Tach N OAC 0 y issan i C l N Cws have been around for quite a while but Nissan s CVVT design allows for significant control over intake and exhaust valve overlap Both the intake and exhaust camshafts are engineered with the CVVT sprocket on the timing chain side and a sensor plate on the other Each sensor plate has teeth whose rotation past a Hall Effect sensor induces a digital voltage signal that the ECM uses for timing purposes nothing strange there However the intake camshaft sensor plate is unique it has a number of teeth based on the cylinder tiring order This is reported by means of the PHASE sensor which would have traditionally been called the camshaft position sensor CMP On the exhaust camshaft the sensor plate has tour equidistant teeth and the exhaust valve timing control position sensor generates a traditional looking square wave The PHASE sensor can also function in place of the crank position sensor in the event of malfunction The ECM can advance or retard both intake and exhaust cams by using oil pressure to actuate the appropriate sprocket in the necessary direction The exhaust valve timing EVT control solenoid changes the valve angle of opening based on the pulse duty ratio signal from the
7. l pressure available to the second high pressure fuel pump mounted on the head At idle the low pressure fuel pump should generate 73 psi Note that special service tools are necessary to remove the low pressure fuel pump on all Nissan vehicles KV101207S0 amp KV99110600 for pump lock ring removal All evaporative emissions components are Inflow process Plunger lift a Inflow check valve C sol d val h ontrol solenoid valve OFF Outflow check valve Open Close also low pressure and purge occurs into the intake air charge as is typical Things get interesting on the high pressure side of the equation A mechanical high pressure fuel pump is attached to the exhaust camshaft and receives fuel trom the low pressure side The high pressure pump forces fuel into the fuel injector rail where pressure builds and remains present even when the vehicle is turned off A fuel rail pressure sensor FRP reports available pressure to the ECM in the form of voltage Using CONSULT you can check live data for this information Expect to see 400 psi at idle or about 1 14V Fuel rail pressure will vary based on the calculated demand for fuel By modulating the high pressure fuel pump control solenoid the ECM can adjust how much high pressure spills back to the low pressure side By default pressure will be low upon solenoid activation a one way valve will close and prevent spillage to increase pressure As solenoid on t
8. le Aetention Retard Angle 10 Nissan TechNews higher voltage is higher pressure The ECM will observe pressure and appropriately route exhaust gas toward the turbo inlet for increased boost or back into the intake through the recirculation valve for decreased boost To adjust boost the computer commands the boost control solenoid to change pressure against a diaphragm within the boost control actuator Longer duty cycle to the boost control solenoid moves the diaphragm open which in turn increases the exhaust flow to the turbo inlet Technicians can use the CONSULT to check the commanded boost solenoid value in live data BOOST S V should read 0 at idle With the accelerator pedal depressed at least halt travel BOOST S V should read 100 below 3000 rpm and somewhere between 30 60 over 3000 rpm Fail Safe Mode Various MIL faults will induce a fail safe mode Check the repair manual for details For example P0045 boost control solenoid circuit sets the boost actuator to zero boost by default PO190 FRP sensor circuit opens the high pressure fuel pump solenoid at all times to provide full pressure at the fuel rail POO87 FRP control circuit may cause limited power due to incorrect fuel pressures As with any diagnostic approach begin with the service manual and common sense before reaching tor complicated explanations 2015 Generational Changes The second generation of the MRI6DDT is standard on 2015 model year
9. lls for 91 octane gasoline for best performance Lower octane fuel can be used but with potential losses to power and efficiency It is lubricated Spill process Outflow process H High pressure fuel out Outflow check valve The ECM manages high fuel pressures by actuating the control valve solenoid and its one way valve f CCA y APANIA C INISSa nN 1ecCri y C VV 3 with 5W 30 API SN oil and cooled using Nissan Genuine Long Lite Blue Coolant Ignition is achieved using long lite iridium tipped spark plugs and direct ignition coils Gasoline Direct Injection DIG Gasoline direct injection is becoming more popular Here we ll focus on the design specifics of the MRI6DDT engine in what Nissan refers to as DIG High pressure fuel injectors are located in the side of the head and are controlled by the ECM in two ways The first notable difference from conventional fuel control is that rather than grounding the injectors the ECM provides up to 65V to power them to spray when necessary Second the ECM commands the high pressure fuel pump control valve solenoid to adjust the pressure and therefore volume of the spray Having such fine control over fuel delivery is truly what makes direct injection such a step forward There are high and low pressure sides of this direct fuel injection system The low pressure side of things looks very much like a traditional design an in tank fuel pump provides constant fue
10. rs They must be Inflow process Low pressure fuel in J Fuel spill out broken in half and defused in a controlled situation Consult the repair manual for exact steps The design of the intake manifold is tied closely to the engine s optimal operating speed The MR16DDT has acoustically equal intake runners that sport secondary tumble valves The tumble valve controller can adjust the runner length as needed by the ECM to introduce turbulence when the engine is very cold or idling When closed the runners are shorter and the velocity of the air charge is greater Upon entering the cylinder the swirling air charge promotes better coalescence with the fuel charge and can also improve the burning speed of the mixture When open the runners are longer and the length of the runners is tuned to reduce intake flow resistance The acoustically equal runner design also adds to the joy of driving by reducing the often rough sounds of intake and dramatizes the pleasant sensation of acceleration Along the same lines of driver experience the MRI6DDT is equipped with a silent timing chain design The naturally occurring impact noise of chain to sprocket mesh is lessened by spreading the impact points from just the pin of the chain to other points on the cam sprocket Distributing the impact lessens the sewing machine type sound The MRI6DDT runs at 9 5 1 compression ratio with a bore and stroke of 79 9mm by 81 1mm It ca
11. s fuel efficiency and maximizes performance MR16DDT It s also worth mentioning that the Nissan JUKE NISMO edition further improves the performance of the stock MR1I6DDT with ECM tuning and modifications to nearly 100 individual components The NISMO RS can output 215 hp thanks to increased exhaust flow trom larger diameter piping enhanced ECM tuning reinforced piston connecting rods and a limited slip differential to ensure the power meets the ground Shiny on the Inside Upgraded Engine Mechanical Parts Friction is an ever present tax on the efficiency of machines From the movement of the pistons to the rotation of the crankshaft there is friction in every tiny engine motion Every bit of power lost due to friction further reduces the net efficiency of any internal combustion engine The MRI6DDT reduces friction by polishing the cam and crank journals to a mirrored Nano tinish Heat management of internal engine components is a critical consideration for reliability and longevity Using a design typically reserved for high performance applications the MRI6DDT has hollow sodium tilled exhaust valves Like shaking a ketchup bottle as each valve moves the force pulls the liquid sodium toward the stem or the face This facilitates the movement of heat away from the hotter face and reduces mechanical wear Sodium is a reactive metal and there are necessary sate handling steps to manage valve disposal atter repai
12. tion event is delayed and the amount of fuel is diminished to extremely lean numbers At the end of the compression stroke the small very rich injection charge is sprayed directly at the spark plug The final mixture is local to the plug electrode but surrounded by lean mixture The ignition event creates a flame front from the rich mixture igniting the remaining air As a result a less homogenous air fuel mixture is needed for compression and combustion which saves fuel overall The MRI6DDT will utilize this technique whenever the engine is cold ECT reads 41 F 104 F Stratified charge combustion increases the rate of warm up and improves emissions At all other times the air fuel mixture is comparable to similar modern engines The injectors themselves are installed directly to the side of the cylinder head Removal and reinstallation of these components requires special service tools Due to the high pressure nature incorrect repair procedures can introduce potentially hazardous tuel leaks Always refer to the service manual before attempting repairs As fuel pressure is ever present within the rail a special fuel pressure release procedure is necessary prior to work Using the CONSULT connect to the ENGINE computer sub category choose WORK SUPPORT then perform FUEL PRESSURE RELEASE Start the engine and after it stalls crank 2 3 more times to release all pressure Turn the ignition off to complete the procedure and beg
Download Pdf Manuals
Related Search