D22 Neutral Position Switch Test
- Thread starter simonk8
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Hi, in reading this my ute doesnt seem to have a problem but can someone clarify for me what the NPS is for (the "heat" switch located botttom right of steering column)? Im guessing you use it in cold climates to help warm the motor up quicker but also, from reading this thread it will stop the car from starting in gear. Thus this is where the surging comes from when in gear as it begins to fail??
The heat switch is there for the Euro market where the temps get down around the -20c mark on a regular basis.
It really isnt needed in Aus at all, although some say they use it when they are winching or running things like compressors, IMO its still not needed.
The switch that fails is on the gearbox and it is there so when the engine is revving higher then idle you cant slam it in gear and potentially damage the box.
So when the switch is playing up its telling the ECU that you have the switch activated when you dont and you are just driving as normal.
When the one went in my old D22 it was first noticed on the freeway at 110kph in 5th but then got worse and was more noticeable in 3rd.
It really isnt needed in Aus at all, although some say they use it when they are winching or running things like compressors, IMO its still not needed.
The switch that fails is on the gearbox and it is there so when the engine is revving higher then idle you cant slam it in gear and potentially damage the box.
So when the switch is playing up its telling the ECU that you have the switch activated when you dont and you are just driving as normal.
When the one went in my old D22 it was first noticed on the freeway at 110kph in 5th but then got worse and was more noticeable in 3rd.
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not sure about damaging the box. more like an emissions thing.
neutral switch reduces the amount of fuel and possibly timing. i guess its to tell the ecu the load on the engine has suddenly changed. sudden changes in load is bad for emissions.
auto's are worse for emissions due to the sudden on/off loading the torque converter creates, hence auto d40 had the DPF fitted and the manual didn't.
neutral switch reduces the amount of fuel and possibly timing. i guess its to tell the ecu the load on the engine has suddenly changed. sudden changes in load is bad for emissions.
auto's are worse for emissions due to the sudden on/off loading the torque converter creates, hence auto d40 had the DPF fitted and the manual didn't.
correct me if im way off Tweak'e, im sure you know allot more then me BUT,
I would of thought Nissan wouldnt really want you slipping it into first or changing gears while the engine is still revving and possibly at the wrong revs not matching the up to the box.
I know my ranger will actually pick the revs up in between changes but the amount of revs changes depending on what gear and how fast you are going when changing into that gear.
when done correct that can help the change but when done wrong can be detrimental, just like in the crash box's get the little blip of throttle just right and the change was smooth get it wrong and your grinding and crunching.
Also i would of thought it would be better for emissions if the engine actually held revs? that way its not always building from low down in the rev range to high up, after all isnt that when you see the most amount of smoke being pumped from the exhaust, when under acceleration?
I would of thought Nissan wouldnt really want you slipping it into first or changing gears while the engine is still revving and possibly at the wrong revs not matching the up to the box.
I know my ranger will actually pick the revs up in between changes but the amount of revs changes depending on what gear and how fast you are going when changing into that gear.
when done correct that can help the change but when done wrong can be detrimental, just like in the crash box's get the little blip of throttle just right and the change was smooth get it wrong and your grinding and crunching.
Also i would of thought it would be better for emissions if the engine actually held revs? that way its not always building from low down in the rev range to high up, after all isnt that when you see the most amount of smoke being pumped from the exhaust, when under acceleration?
the nps dosn't limit rpm. you can still rev its nuts off during a gear change. it still provides more than enough fuel for bad gear changing. while it may help reduce damage from bad gear change i don't think its the primary function.
its not the rpm that effects the emissions, its the load. in particular suddenly changing load.
fairly common for diesels to puff a small bit of smoke on a gear change. i suspect its there just help reduce that.
its not the rpm that effects the emissions, its the load. in particular suddenly changing load.
fairly common for diesels to puff a small bit of smoke on a gear change. i suspect its there just help reduce that.
Nitnat
Member
Just thought I would put my $0.02 in here.
My navara has always felt 'gutless' in 4th gear, and to a lesser extent quite underpowered in 3rd also.
I googled up possible reasons and got relinked back here of course.
I did the NPS test and the revs didn't drop in 3rd or 4th. Perfect I thought, must be it!
I located the NPS from inside the cab looking down, tried to disconnect it and couldn't figure out how to unclip the bugger. So.... I deliberated for a good minute perhaps two, and then just cut the wires.
Put it back together and took it for a run. TOTALLY different truck, put a smile on my face. Hands down BEST performance thing I have done lol
Matt
My navara has always felt 'gutless' in 4th gear, and to a lesser extent quite underpowered in 3rd also.
I googled up possible reasons and got relinked back here of course.
I did the NPS test and the revs didn't drop in 3rd or 4th. Perfect I thought, must be it!
I located the NPS from inside the cab looking down, tried to disconnect it and couldn't figure out how to unclip the bugger. So.... I deliberated for a good minute perhaps two, and then just cut the wires.
Put it back together and took it for a run. TOTALLY different truck, put a smile on my face. Hands down BEST performance thing I have done lol
Matt
Nitnat
Member
It doesn't increase performance per se.
It just gives you what you should have had all along, that has been restricted by a faulty NPS.
It just gives you what you should have had all along, that has been restricted by a faulty NPS.
Hey ante how did you go?? Did the idle rev drop back down?? My mates ute has the very same issue so I'll try the same thing, he said it was surging the other day now it's no longer surging but idles high about the same as yours. I'll have a look this week.
Cheers Steve.
Nitnat
Member
I would suggest just disconnecting the one switch.
It is the one at the top of the gearbox furtherest towards the back (tail shaft end) Where it goes into the gearbox it is blue in colour.
Disconnect that one, start it up and then flick your heat switch on. The revs will no longer increase at all.
cheers
Matt
Yeah I'll give it a go, strange it seems to operate correctly, it idles high when switched on, it drops when put in gear, but the ute itself is idling high with it switched off, funny thing is when it's switched on and in gear it idles as it's supposed to when it's off. Hope that makes sense. When it's off te ute idles high when it's on in gear it idles normal.
I think the main purpose of the NPS is so the ecu knows when your travelling at speed, and you back off while in gear, it can cut the fuel at" accelerator pedal fully closed " to save fuel.When the cars moving and in gear its momentum keeps the engine turning over with no fuel needed, but if its in neutral then it needs to inject fuel to keep the engine running under the same situation.
