Tricky-Ricky

Most modern MAFs are hot wire,and the DE is no exception, but there are other variations,so your mates BMW could be a membrane type, but there is also laminar flow, Karman, moving vane, and cold wire sensors, older BMW and VW used to use Karmen , and moving vane types. Hot wire is usually used in conjunction with an air temp sensor to determine volume density, most use a 0-5V signal, but some use a frequency output form a film rather than a wire, As I said I have yet to own a car where the MAF has failed, or has exhibited symptoms of incorrect airflow signal due directly to the MAF itself, so not sure why your worrying. Edit, just found these which may help. https://www.oscium.com/sites/default/files/MAF_autoshop101.pdf http://www.knfilters.com/MAF/MAFDevices.htm

In order to check a MAF, you would need to be able to reference the std calibration figures/scale, I have never seen them in any manual, just idle and WOT figures on other Nissan's, so kind of difficult to check for the average owner, unless you can access the std ECU, and log load vs voltage output. Must admit I have never come across a problem with the MAFs on the few aging cars I have owned with a MAF.

I presume your talking about the Kinetix plenum? generally speaking they are more suited to FI than N/A, you wont see much gain, if any, and likely a loss without a remap.

Cold viscosity will make very little difference in our climate, so 5w or 10w will be fine, 40 will be slightly more viscous than 30 at normal running temp, so is better suited to a high mileage or hard used engine.

What are you attempting to do clear a CEL? and how are you resetting?

I would stick to 5W40 for the simple reason that its been run on that grade, and it now has higher mileage, if you revert to 5w30 it will likely result in lower oil pressure.

Pretty sure that the lambda sensors on the Z are 2v wide-bands rather than 5v, that why you end up with an odd reading on some loggers/diagnostic machines and dashboard apps, but the higher reading on one back is normal.

Quick answer is no! you will find no scientific evidence, only than hearsay and promotional blurb that any one type of plug is better than another, they have been manufacturing plugs for over a century and so far nobody has come out with a better design.

Exactly! nothing to be gained with iridiums apart from service life, anything else is just placebo.

Its the full throttle/high load breather,There is no real disadvantage to leaving that one alone as it will not transfer much oil vapor to the intake, plenty of info in the is thread if you want to know more and the options. http://www.350z-uk.com/topic/89535-oil-catch-can/#entry1349925

Here is a clearer pic for you,

Initially I was going to say fans, but as they have been replaced, so could be an air lock but I doubt it after this time, are you sure the fans are wired correctly and pulling air flow through the rad and not blowing? Otherwise I would say it could be a head gasket, however it could simply be a case of the std rad is now not big enough to provide decent cooling with the extra power/heat being generated, are you sure the rad is not partially blocked, and not restricting cooling, IE internally or perhaps externally with an obscuring body kit?

My advice would be don'tIt's there for a reason well several really to prevent damage to the turbo especially if it has ceramic blades as some Celica's and Mr2's had from the factory to stop the turbo stalling, which will increase lag and stop over-pressure in the system between the turbo and the throttle body causing potential damage this was caused when the vacuum hose came off my BOV if you really want this sound then get an adjustable BOV so you still have some protection Turbos only have ceramic blades on the exhaust turbine, not the compressor, these are always metal or nylon, neither will be damaged by having no BOV. well since i'm obviously dumb i lifted this straight off Garrett's site but what do they know Q. What is compressor surge? A. The surge region, located on the left-hand side of the compressor map (known as the surge line), is an area of flow instability typically caused by compressor inducer stall. The turbo should be sized so that the engine does not operate in the surge range. When turbochargers operate in surge for long periods of time, bearing failures may occur. When referencing a compressor map, the surge line is the line bordering the islands on their far left side. Compressor surge is when the air pressure after the compressor is actually higher than what the compressor itself can physically maintain. This condition causes the airflow in the compressor wheel to back up, build pressure, and sometimes stall. In cases of extreme surge, the thrust bearings of the turbo can be destroyed, and will sometimes even lead to mechanical failure of the compressor wheel itself. Common conditions that result in compressor surge on turbocharger gasoline engines are: -A compressor bypass valve is not integrated into the intake plumbing between the compressor outlet and throttle body (BOV) -The outlet plumbing for the bypass valve is too small or restrictive -The turbo is too big for the application I'll add one more thing, compressor surge is not compressor stall they are two different things..

My advice would be don'tIt's there for a reason well several really to prevent damage to the turbo especially if it has ceramic blades as some Celica's and Mr2's had from the factory to stop the turbo stalling, which will increase lag and stop over-pressure in the system between the turbo and the throttle body causing potential damage this was caused when the vacuum hose came off my BOV if you really want this sound then get an adjustable BOV so you still have some protection Turbos only have ceramic blades on the exhaust turbine, not the compressor, these are always metal or nylon, neither will be damaged by having no BOV.

Err remove the BOV and block off the mount/pipes, it will have either a mount that fixes it to a boost pipe, or a hose from said boost pipe, and a small trigger pipe from a vacuum source.

I have never heard or experienced this happening, for the reasons I have already mentioned, its not possible to get enough flow back through the still spinning turbo compressor impeller, as it breaks up any flow, besides once the throttle plate is closed, which sends a voltage signal to the ECU, it then shuts off the injectors so no more fuel can be added anyway.

Really never heard of that happening before now, I think it may well have been due to another problem, and not related to the AFM and boost,unless it was faulty.

Which scenario are you referring to? Boosted with BOV, or boosted without? With BOV the already metered air is dumped, so ECU has already added the correct fuel, but as some of this air has been dumped, the fuelling is rich. Without BOV there is no change in fuelling when the throttle is shut, as the metered air is the same, so fuelling is correct.

Its simple, with no dump of airflow that already been read by the ECU, the mixture is correct and not rich, I think your trying to over think it, there is not enough air movement in reverse for an AFM to read, although I am pretty sure it could read in reverse as its not directional, An AFM reads the cooling effect that airflow has, its basically a heated wire that shows a voltage increase as its cooled Also when the throttle plate is shut there is the closed voltage signal sent to the ECU which in response will shut off the injectors, its a bit more complicated than that but...

No because the MAF has pre read the airflow and ECU has already added the correct amount of fuel, throttle closes, DV dumps the now presuriasd system, but because the mixture is now over rich, it tends to ignite in the hot exhaust, don't forget you dealing with micro seconds at say 5-7K RPM, and usually highish boost pressure.

I thought this would inspire a lot of debate, anyway if a turbo motor has a MAF/AFM and is fitted with a dump valve, because the air has already been metered and the dump valve lets off the metered/pressurized air, the resulting fuel air mixture will be momentarily over rich, which in some circumstances can result in partial stall, but normally it will just cause the unburnt mixture to ignite in the exhaust, (if hot enough) giving the characteristic pop/bang. Unlike turbo engines that are fitted with a MAP sensor (mass air pressure) which are usually fitted to the plenum and so only measure the volume of air that already past the dump valve, so the mixture remains stable, these are much better suited to a turbocharged engine. Now I have never heard of a non dump valve system killing a AFM because of the throttle being closed, the airflow would need to not only flow back at enough pressure and turbulence, which is Highly unlikely due to the volume in the system, IE pipework and intercooler, it would also have to get through the still sinning compressor turbine, and still retain enough force to do damage... I don't think so. There have been many debates regarding whether fitting or not fitting a dump valve is better for the turbo or not, and as far as I know the jury is still out, its all opinions and conjecture,, I personally have run with and without, and neither method has been any longer lasting than the other, and re spool has also been negligible even on a big turbo, I like the flutter sound better than a dump myself. I also hope that the confusion between a dump valve and a waste gate has been put to bed. Edit, also just noticed that someone had the thought to mention using a blow through system, which I forgot about, which is another reason I seriously doubt pressure/airflow would kill an AFM.

LOL! yes no waste gate and your replacing your motor, on the other hand not running a dump valve wont cause any problems, other than perhaps an a minimal slowness in re spool if you have a big turbo, if you want flutter and are running a dump valve just adjust it so it doesn't dump to easily, that way you can have the best of both a nice tish, and flutter.

I could probably beat that story, when it comes to moving house.......but I think ill wait until I am bored and can deal with the typer's cramp.

There is always is a difference between O2 readings from one bank to the other, and now I have seen that the sensors are cycling as they should, I would say that now looks OK to me, similar to some of the logs I have taken from the std ECU. But its worth keeping an eye, as it could be a lazy sensor or on its way out, but I wouldn't worry too much for now, it will throw a CEL should the sensor go down.

O2 sensor 1 of bank 1 and 2 are used by the ECU to monitor for the correct air fuel mix, whereas sensors 2 of bank 1 and 2 are the cat monitors, and use a much reduced signal variation and cycle, and in normal circumstances not used to monitor fuel mix, and so will show a completely different reading to sensors 1. However on looking at your gauges again it would seem that it is reading sensors 1, a so it would seem that one sensor is reading low, which would indeed prompt the ECU to add more fuel, Does that reading change much at various RPM/load? if not then that a fair indication that the sensor is dead.