Losing power over 4000 RPM

Have you tried using the onboard diagnostic system and pulling codes? Also, did this problem happen when you first bought the car, or is it a recent occurrence?

Yes I tried to see any code of fail and nothing show up when I put the scanner and also yes when I bought the car show this failure. I thought could be easy to fix but now I’m worried about. I have an idea of would be an electrical issue or variable control timing.

So the car runs well below 4000 RPM?

Yes the car runs fine under 4000 rpm and I just forgot to mention I had the ABS Light on beacuse I have code C1106 rear left abs sensor fail. I will check if it’s the Abs sensor.

NicoBigZ33 said:

Yes the car runs fine under 4000 rpm and I just forgot to mention I had the ABS Light on beacuse I have code C1106 rear left abs sensor fail. I will check if it’s the Abs sensor.

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That's important to mention all the lights and codes that are appearing. Like most modern vehicles, your Z can respond to any system failure in the car. This could trigger a reduction of revs for safety reasons. If your Z is anything like our USDM Z33s, you'll find the ABS sensor harness is located near the rear diff and branching off to both axles.

Beyond the ABS light, have you tried a backup key? If your Z is anything like our USDM Z33s, Nissan provided valet keys that restricted speed and revs for owners. My factory valet key has a burgundy-colored handle.

dkmura said:

Beyond the ABS light, have you tried a backup key? If your Z is anything like our USDM Z33s, Nissan provided valet keys that restricted speed and revs for owners. My factory valet key has a burgundy-colored handle.

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I just bought a new set of spark plugs and the rear abs sensor. I just did some tests on my actual abs sensor and it seems to be wrong. So I'm waiting to receive my purchase to change it and try again if the engine runs above 4000 rpm.

I don't have my valet key so it's not part of my plan right now. If you have the part number please send me. Because I just searched the web and also Z1 Motorsports and found nothing.

I'm going to change the abs sensor and do some tests, if the car runs the same as now I'm going to buy the camshaft + crankshaft sensor and I'm also thinking maybe I have problems with my variable timing control solenoid. Because it has a rare sound and my engine doesn't seem to work with the variable valve timing.

Mentioned the valet key thinking you might be using one for your car. You'd know it on sight as it's different than the usual black moulded handle. No part # that I know of. As for the variable timing control solenoid, it's surprising that you haven't had a code if it's malfunctioning. What kind of code reader are you using?