JDM 300zx 1995 LIMP mode problem

[LambregtsImport]

Hi all my 300zx fans.

 

My name is Dave from the Netherlands.

 

Recently I imported a 300ZX ( Fairlady Z Z32 ) from japan, and it will be fully restored.

 

But it seems to be in Limp mode, it will not rev above 2500 rpm's.

 

I alreayd replaced the MAF and that seems to work good. And did a lot of research but I just can not get it out of limp mode.

 

I also tested the ACC mode 2 and tested the o2 sensors, they dont seem to work, so both lambda's will be replaced.

 

I get the following error codes, can you guys seem to guess what the error codes mean:

 

https://www.youtube.com/watch?v=vXreJ6jdHsM&feature=youtu.be

 

 

 

Thanks in advance for all the help.

 

I really hope to get this fixed, because i has been taking me months now, and I'm slowly turning gray :'(

 

 

Greetings,

Dave

[JeffTT]

The codes below you are getting look to be a combination of live and old codes, the det crcuit will need attention once you have sorted your present problem but don`t worry it will not be effecting anything yet.

 

Code 12 AFM ( maf )

 

Code 13 Water temp sensor

 

Code 34 Det sensor circuit

 

The water temp sensor code is most likely a bad connection and caused when working in that area or running the engine with it not connected, check / clean and refit the sensor connector.

 

The afm code could be the original afm or the one you have fitted now is faulty or you ran the engine with the afm disconnected.

 

So best thing is clear all codes easy way to leave the battery disconnected for an hour or so, then run another code test without starting the engine, you will then see what you have, if clear run the engine and do another test see what has come back. My guessing is the second maf you have tried is also faulty as the 2,500 rpm cut off is afm every time, when you have resolved the issue with the running look at your det sensor circuit as this will keep the power down until resolved.

 

Jeff

[Gaz 300]

Welcome Dave and hope you get it running right.

[LambregtsImport]

The codes below you are getting look to be a combination of live and old codes, the det crcuit will need attention once you have sorted your present problem but don`t worry it will not be effecting anything yet.

 

Code 12 AFM ( maf )

 

Code 13 Water temp sensor

 

Code 34 Det sensor circuit

 

The water temp sensor code is most likely a bad connection and caused when working in that area or running the engine with it not connected, check / clean and refit the sensor connector.

 

The afm code could be the original afm or the one you have fitted now is faulty or you ran the engine with the afm disconnected.

 

So best thing is clear all codes easy way to leave the battery disconnected for an hour or so, then run another code test without starting the engine, you will then see what you have, if clear run the engine and do another test see what has come back. My guessing is the second maf you have tried is also faulty as the 2,500 rpm cut off is afm every time, when you have resolved the issue with the running look at your det sensor circuit as this will keep the power down until resolved.

 

Jeff

 

Hi jeff,

First of al, thanks a lot for sorting out the codes, you are a true hero.

 

Code 12: The engine has ran without the MAF sensor plugged in to see what happend. The new ordered maf seems to work, because when plugged out and in the idle rpm's seem so change. Also I measured all the MAF sensor wires and they seem to function correct, all fout of them.

 

Code 13 Water temp sensor : The engine has ran without the temperature sensor connected. AM I right if I say that when i unplug the temperature sensor my FAN starts to spin like a mad man? Or is that not the correct temperature sensor? If not, where is this temperature sensor fitted? So I can test the wires and get some connection spray on the sensor.

 

Code 34 I have no idea what a DET sensor is, could you explain that? And where it is located?

 

Those first two codes seem reasonable and easy to fix.

 

I will cut the power tonight for about an hour and then recheck.

 

Thanks a lot!!!

 

- - - Updated - - -

 

Welcome Dave and hope you get it running right.

 

Thanks a lot! I feel very welcome on this forum, even though I am a foreigner to you guys :)

[LambregtsImport]

IS this the correct DET sensor?

And what does this DET sensor exactly do?

 

[Funkysi]

That's the DET sensor connector, the actual sensor is buried at the back between the heads. The sensor is basically a microphone that listens for engine knocking/pinking. If it does, the ECU would put itself into a limp mode (increased fueling and reduced boost) to prevent this.

[LambregtsImport]

That's the DET sensor connector, the actual sensor is buried at the back between the heads. The sensor is basically a microphone that listens for engine knocking/pinking. If it does, the ECU would put itself into a limp mode (increased fueling and reduced boost) to prevent this.

 

Hi,

The word "knocking" got me sweating.

Does that mean its like a rod knock or something extremely bad?

[Funkysi]

No, it's only to do with the noise the sensor would pick up under pre-ignition. The sensor is often called a 'knock sensor'.

[Gaz 300]

You maybe have seen this link but here it is anyway.

 

http://zhome.com/ZCMnL/PICS/detonationSensor/detonationSensor.html

[LambregtsImport]

You maybe have seen this link but here it is anyway.

 

http://zhome.com/ZCMnL/PICS/detonationSensor/detonationSensor.html

 

Not a big fan of that to be honest. Might kill the engine...

Did anyone on this forum ever try it, and succeeded?

[Funkysi]

It's been done many times and I've not seen any issues. The issues come when you run very high boost and bypass it, especially with a standard chip.

 

There is a way of relocating the DET sensor - it's been discussed a number of times on twinturbo.net and there's even a kit for it.

 

http://www.yugobernie.com/det_sensor.html

 

I'm not totally convinced that the sensor would be picking up the most accurate detail, but again, not heard any issues of this being used either.

[lymon]

Hello Dave, not sure where you are located, but as I am in the Netherlands also... you can contact me (eric-at-300zx-twinturbo.com) if you want.

I can connect a computer with the conzult software to your car and see what's the exact problem.

[Richie K]

Welcome to the Club Dave, hope you get it all sorted:thumbup1:

[LambregtsImport]

Hello Dave, not sure where you are located, but as I am in the Netherlands also... you can contact me (eric-at-300zx-twinturbo.com) if you want.

I can connect a computer with the conzult software to your car and see what's the exact problem.

 

Hello eric,

Im now making the new video for the new codes.

And its all just bad news...

 

I'm so scared this project will never be finished, since my appointment at the bodywork guy and painter is next month.

I'm seriously worried sick.

 

I WILL mail you :)

[LambregtsImport]

After having my minus plug off for about 90 minutes.

These were the codes without starting and just in ACC mode.

 

Good luck guys and thanks in advance :

[video=youtube_share;n4VgWITgkKk]https://youtu.be/n4VgWITgkKk

[ted]

See if this helps you out mate The Ultimate Guide to Z32 Self-Diagnostics

[LambregtsImport]

You know what I find so strange.

My ECO never ever blinked. I read the codes via my engine check light.

 

The led inside my ecu does not seem to function in any way.

[JeffTT]

Ok your codes again still show the det sensor as before, you could try inserting a "by pass resister" of 1 meg ohm ( see pic below ) as a test to clear that code ( will need battery removed again or codes cleared via ConZult)

 

Code 12 again the maf sensor suggests as before a fault air flow meter or a fault with the loom to it.

 

 

Code 34 Det sensor

 

Code 12 Maf sensor

 

Regards

 

Jeff

 

[ted]

You can still clear your fault codes once you cleaned the parts by undoing the battery for while

[Alic]

You can still clear your fault codes once you cleaned the parts by undoing the battery for while

He has ted

 

After having my minus plug off for about 90 minutes.

These were the codes without starting and just in ACC mode.

[LambregtsImport]

He has ted

 

Strange thing is, on that guide " The Ultimate Guide to Z32 Self-Diagnostics ", they say that is not the way to clear the codes and retest. So I think I have to try it again

[LambregtsImport]

Ok your codes again still show the det sensor as before, you could try inserting a "by pass resister" of 1 meg ohm ( see pic below ) as a test to clear that code ( will need battery removed again or codes cleared via ConZult)

 

Code 12 again the maf sensor suggests as before a fault air flow meter or a fault with the loom to it.

 

 

Code 34 Det sensor

 

Code 12 Maf sensor

 

Regards

 

Jeff

 

[ATTACH=CONFIG]93544[/ATTACH]

 

With the det sensor I will try such a resister and see what happens. I can just get them in my local hardware store I assume?

 

The MAF sensor is still blowing my mind, since that is a aftermarket brand new one.

 

Maybe after all me codes are not cleared?

I also count a code 13 in the video ; coolant temp sensor, do you too?

[JeffTT]

The MAF sensor is still blowing my mind, since that is a aftermarket brand new one.

 

Aha ! after market ones, especially if bought off E-bay do not work!

 

Jeff

[LambregtsImport]

Well darn....

But OEM they are waaaaaay to expensive

[JeffTT]

Well darn....

But OEM they are waaaaaay to expensive

 

Yes they are, unfortunately the copy ones from China just do not work, just checked on E-bay and the company that was selling them here is no where to be found now, so figures it did not work out.

 

Best bet is to see if you can beg or borrow one to try of another zed owner, failing that buy one second hand that is tested and warranted, usually go for around £100 used here in the UK, and If that fixes the issue which I am sure it will its not too bad, at least then you can return the copy one for a refund hopefully.

 

Jeff