Mysterious 1jz problem - ECU code 12

[cybersimon]

Hi all,

I've almost finished my JZX90 1jz-gte into MX83 cressida conversion, and I'm completely stumped on a problem that causes the engine to not rev over about 3,500RPM. Besides this the car runs perfectly, it will sit there and idle all day, and basically always starts first time.

I have checked the ECU for error codes and code 12 keeps coming up. Even if I clear the ECU then check for codes before even cranking the engine I still get code 12. I presume this code is causing the ECU to run in limp mode and hence not rev over 3,500.

So, I checked on this site:
http://mkiv.supras.org.nz/techo.htm#ENGINE_CODES
And it says that code 12 is either one of the camshaft position sensors, or the crankshaft position sensor.
I have checked the resistance of each of these sensors at the ECU plug, and they appear to be all the same, around 1.1k, so I'm inclined to think that its not a wiring problem with one of these sensors.

I should also add that I have tried 2 different ECUs, and both come up with the same code even before the engine is turned over.

I can only assume its wiring related, but even my mate that wired the car and has wired up a few of these before is unsure what the problem could be.

Any help with this would be much appreciated!

[triptek]

Read through the following page mate. The neutral start switch isn't wired correctly. I explain how to fix it in one of the last posts on the following page.

http://www.toymods.net/forums/showth...699#post870699

[cybersimon]

Thanks heaps for the info triptek. Myself and my mate worked out what additions to make to the wiring based on the info you provided, and now the car runs like a dream.

Now if I can just get the ABS to work I'll be complete...