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- Thread starter senna1
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Be good to know, which is fact as the whole idea of seeing what the valve is doing,, duty cycle especially for boost control, ie if bleeding off more air= more boost,
or Egr to see if more air is being cycled into the inlet manifold,, which at the wrong time can cause running problems.
Do some groundwork yourself & work it out it's not rocket science, it's been said time & again on here that VCDS reports what the ECU allows you to see, it's your job from then on to use technical info & system knowledge to evaluate what's going on !
This is a forum! to help each other,, do you know the questions above, it must of been asked many times before, seems no knows for sure on this forum,, i've since found out myself
now to check it out on the vehicle,, i was trained in the ford school with sierra cosworth escort rs turbo's etc, different boost control , no amal valve, but idea the same as all use duty cycle map, most now varible vane turbo's so little different, and egr v's mass air flow n18.
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Well I have seen guys invert the duty cycle and create a reverse opening noid to allow or not allow vacuum or boost to control a VNT or traditional WG ........with stock stuff, and no DTC's because it controlled the range.
If looking at boost request verse actual a lot can be determined.........same goes for the EGR by disabling and watching the offset achieved in actual boost if looking for a parasite.
Guys saw net gains with older type turbo from AHU installed on ALH with get this ? Lower NOX levels.
If looking at boost request verse actual a lot can be determined.........same goes for the EGR by disabling and watching the offset achieved in actual boost if looking for a parasite.
Guys saw net gains with older type turbo from AHU installed on ALH with get this ? Lower NOX levels.
Because it's like asking, "Is an oil pressure switch normally open or normally closed?" There is no correct answer. It depends on which switch and what engine.
-Uwe-
well i found the answer to my question regarding duty cycle, because for vw using the n18 procedure the same, oil pressure switch is much easier to guess, what i needed to to know to confirm was the duty cycle request as to know what the command from the ecu was telling the n18 to vary the egr actuator. if you dont know the correct funtion of the duty cycle
you dont know if the egr actuator should be open or closed, no good in just using 03 output test you can hear the engine response, but not whether the egr should be closed fully, slightly open, all for different driving cycles, especially for starting the engine from cold, you need to know the correct understanding for n18 duty cycle. no point in reading it backwards which could be the case if you dont know if 0 is closed or 100% is open vise versa.
Thank you jack. at the end of the day the n18 is just cycling air, early boost control, on the old stuff you just bled air away from the turbo actuator, some used after market bleed valve, but then no safety function if the turbo air temp was very high for example you would still see maximum boost, there is no built in safety for the engine
but with the old fords you had safety as the boost would be dropped to actuator pressure and ignition retarded, i have even used a piece of copper pipe with a hole in it, home made bleed vave,
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Well the 1Z AHU ALH etc > on all use a MAP sensor whether internal or external, and if you don't make or exceed the specified boost request.......... there is a safety in EDC15 to shut down fuel and LIMP.
Control on n75. i have a log here. regarding egr duty cycle Do you know why vcds it shows two lots of duty cycle % for egr. on mvb 041 003.
Friday,02,October,2015,14:40:42:46146
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 7 x64
VCDS Version: 15.7.1.0 (x64)
Data version: 20150904
www.Ross-Tech.com
VIN: License Plate: LIVE DATA 2
Address 01: Engine (03G 906 016 HN)
14:40:13
63.0°C Coolant Temperature (G62)
861 /min Engine Speed (G28)
185.0 mg/str Exhaust Gas Recirculat. (spec.)
215.0 mg/str Exhaust Gas Recirculat. (actual)
4.8 % Exhaust Gas Recirc. Duty Cycle
210.0 mg/str Mass Air Flow (actual)
19.1 % Position (Spec.) Intake Flap
95.6 % Exhaust Gas Recirc. Duty Cycle
19.1 % Position (Act.) Intake Flap
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